1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* message.c - synchronous message handling
4	*
5	* Released under the GPLv2 only.
6	*/
7
8	#include <linux/acpi.h>
9	#include <linux/pci.h> /* for scatterlist macros */
10	#include <linux/usb.h>
11	#include <linux/module.h>
12	#include <linux/of.h>
13	#include <linux/slab.h>
14	#include <linux/mm.h>
15	#include <linux/timer.h>
16	#include <linux/ctype.h>
17	#include <linux/nls.h>
18	#include <linux/device.h>
19	#include <linux/scatterlist.h>
20	#include <linux/usb/cdc.h>
21	#include <linux/usb/quirks.h>
22	#include <linux/usb/hcd.h> /* for usbcore internals */
23	#include <linux/usb/of.h>
24	#include <asm/byteorder.h>
25
26	#include "usb.h"
27
28	static void cancel_async_set_config(struct usb_device *udev);
29
30	struct api_context {
31	struct completion done;
32	int status;
33	};
34
35	static void usb_api_blocking_completion(struct urb *urb)
36	{
37	struct api_context *ctx = urb->context;
38
39	ctx->status = urb->status;
40	complete(&ctx->done);
41	}
42
43
44	/*
45	* Starts urb and waits for completion or timeout. Note that this call
46	* is NOT interruptible. Many device driver i/o requests should be
47	* interruptible and therefore these drivers should implement their
48	* own interruptible routines.
49	*/
50	static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
51	{
52	struct api_context ctx;
53	unsigned long expire;
54	int retval;
55
56	init_completion(x: &ctx.done);
57	urb->context = &ctx;
58	urb->actual_length = 0;
59	retval = usb_submit_urb(urb, GFP_NOIO);
60	if (unlikely(retval))
61	goto out;
62
63	expire = timeout ? msecs_to_jiffies(m: timeout) : MAX_SCHEDULE_TIMEOUT;
64	if (!wait_for_completion_timeout(x: &ctx.done, timeout: expire)) {
65	usb_kill_urb(urb);
66	retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
67
68	dev_dbg(&urb->dev->dev,
69	"%s timed out on ep%d%s len=%u/%u\n",
70	current->comm,
71	usb_endpoint_num(&urb->ep->desc),
72	usb_urb_dir_in(urb) ? "in" : "out",
73	urb->actual_length,
74	urb->transfer_buffer_length);
75	} else
76	retval = ctx.status;
77	out:
78	if (actual_length)
79	*actual_length = urb->actual_length;
80
81	usb_free_urb(urb);
82	return retval;
83	}
84
85	/*-------------------------------------------------------------------*/
86	/* returns status (negative) or length (positive) */
87	static int usb_internal_control_msg(struct usb_device *usb_dev,
88	unsigned int pipe,
89	struct usb_ctrlrequest *cmd,
90	void *data, int len, int timeout)
91	{
92	struct urb *urb;
93	int retv;
94	int length;
95
96	urb = usb_alloc_urb(iso_packets: 0, GFP_NOIO);
97	if (!urb)
98	return -ENOMEM;
99
100	usb_fill_control_urb(urb, dev: usb_dev, pipe, setup_packet: (unsigned char *)cmd, transfer_buffer: data,
101	buffer_length: len, complete_fn: usb_api_blocking_completion, NULL);
102
103	retv = usb_start_wait_urb(urb, timeout, actual_length: &length);
104	if (retv < 0)
105	return retv;
106	else
107	return length;
108	}
109
110	/**
111	* usb_control_msg - Builds a control urb, sends it off and waits for completion
112	* @dev: pointer to the usb device to send the message to
113	* @pipe: endpoint "pipe" to send the message to
114	* @request: USB message request value
115	* @requesttype: USB message request type value
116	* @value: USB message value
117	* @index: USB message index value
118	* @data: pointer to the data to send
119	* @size: length in bytes of the data to send
120	* @timeout: time in msecs to wait for the message to complete before timing
121	* out (if 0 the wait is forever)
122	*
123	* Context: task context, might sleep.
124	*
125	* This function sends a simple control message to a specified endpoint and
126	* waits for the message to complete, or timeout.
127	*
128	* Don't use this function from within an interrupt context. If you need
129	* an asynchronous message, or need to send a message from within interrupt
130	* context, use usb_submit_urb(). If a thread in your driver uses this call,
131	* make sure your disconnect() method can wait for it to complete. Since you
132	* don't have a handle on the URB used, you can't cancel the request.
133	*
134	* Return: If successful, the number of bytes transferred. Otherwise, a negative
135	* error number.
136	*/
137	int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
138	__u8 requesttype, __u16 value, __u16 index, void *data,
139	__u16 size, int timeout)
140	{
141	struct usb_ctrlrequest *dr;
142	int ret;
143
144	dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
145	if (!dr)
146	return -ENOMEM;
147
148	dr->bRequestType = requesttype;
149	dr->bRequest = request;
150	dr->wValue = cpu_to_le16(value);
151	dr->wIndex = cpu_to_le16(index);
152	dr->wLength = cpu_to_le16(size);
153
154	ret = usb_internal_control_msg(usb_dev: dev, pipe, cmd: dr, data, len: size, timeout);
155
156	/* Linger a bit, prior to the next control message. */
157	if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
158	msleep(msecs: 200);
159
160	kfree(objp: dr);
161
162	return ret;
163	}
164	EXPORT_SYMBOL_GPL(usb_control_msg);
165
166	/**
167	* usb_control_msg_send - Builds a control "send" message, sends it off and waits for completion
168	* @dev: pointer to the usb device to send the message to
169	* @endpoint: endpoint to send the message to
170	* @request: USB message request value
171	* @requesttype: USB message request type value
172	* @value: USB message value
173	* @index: USB message index value
174	* @driver_data: pointer to the data to send
175	* @size: length in bytes of the data to send
176	* @timeout: time in msecs to wait for the message to complete before timing
177	* out (if 0 the wait is forever)
178	* @memflags: the flags for memory allocation for buffers
179	*
180	* Context: !in_interrupt ()
181	*
182	* This function sends a control message to a specified endpoint that is not
183	* expected to fill in a response (i.e. a "send message") and waits for the
184	* message to complete, or timeout.
185	*
186	* Do not use this function from within an interrupt context. If you need
187	* an asynchronous message, or need to send a message from within interrupt
188	* context, use usb_submit_urb(). If a thread in your driver uses this call,
189	* make sure your disconnect() method can wait for it to complete. Since you
190	* don't have a handle on the URB used, you can't cancel the request.
191	*
192	* The data pointer can be made to a reference on the stack, or anywhere else,
193	* as it will not be modified at all. This does not have the restriction that
194	* usb_control_msg() has where the data pointer must be to dynamically allocated
195	* memory (i.e. memory that can be successfully DMAed to a device).
196	*
197	* Return: If successful, 0 is returned, Otherwise, a negative error number.
198	*/
199	int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request,
200	__u8 requesttype, __u16 value, __u16 index,
201	const void *driver_data, __u16 size, int timeout,
202	gfp_t memflags)
203	{
204	unsigned int pipe = usb_sndctrlpipe(dev, endpoint);
205	int ret;
206	u8 *data = NULL;
207
208	if (size) {
209	data = kmemdup(driver_data, size, memflags);
210	if (!data)
211	return -ENOMEM;
212	}
213
214	ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
215	data, size, timeout);
216	kfree(objp: data);
217
218	if (ret < 0)
219	return ret;
220
221	return 0;
222	}
223	EXPORT_SYMBOL_GPL(usb_control_msg_send);
224
225	/**
226	* usb_control_msg_recv - Builds a control "receive" message, sends it off and waits for completion
227	* @dev: pointer to the usb device to send the message to
228	* @endpoint: endpoint to send the message to
229	* @request: USB message request value
230	* @requesttype: USB message request type value
231	* @value: USB message value
232	* @index: USB message index value
233	* @driver_data: pointer to the data to be filled in by the message
234	* @size: length in bytes of the data to be received
235	* @timeout: time in msecs to wait for the message to complete before timing
236	* out (if 0 the wait is forever)
237	* @memflags: the flags for memory allocation for buffers
238	*
239	* Context: !in_interrupt ()
240	*
241	* This function sends a control message to a specified endpoint that is
242	* expected to fill in a response (i.e. a "receive message") and waits for the
243	* message to complete, or timeout.
244	*
245	* Do not use this function from within an interrupt context. If you need
246	* an asynchronous message, or need to send a message from within interrupt
247	* context, use usb_submit_urb(). If a thread in your driver uses this call,
248	* make sure your disconnect() method can wait for it to complete. Since you
249	* don't have a handle on the URB used, you can't cancel the request.
250	*
251	* The data pointer can be made to a reference on the stack, or anywhere else
252	* that can be successfully written to. This function does not have the
253	* restriction that usb_control_msg() has where the data pointer must be to
254	* dynamically allocated memory (i.e. memory that can be successfully DMAed to a
255	* device).
256	*
257	* The "whole" message must be properly received from the device in order for
258	* this function to be successful. If a device returns less than the expected
259	* amount of data, then the function will fail. Do not use this for messages
260	* where a variable amount of data might be returned.
261	*
262	* Return: If successful, 0 is returned, Otherwise, a negative error number.
263	*/
264	int usb_control_msg_recv(struct usb_device *dev, __u8 endpoint, __u8 request,
265	__u8 requesttype, __u16 value, __u16 index,
266	void *driver_data, __u16 size, int timeout,
267	gfp_t memflags)
268	{
269	unsigned int pipe = usb_rcvctrlpipe(dev, endpoint);
270	int ret;
271	u8 *data;
272
273	if (!size || !driver_data)
274	return -EINVAL;
275
276	data = kmalloc(size, memflags);
277	if (!data)
278	return -ENOMEM;
279
280	ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
281	data, size, timeout);
282
283	if (ret < 0)
284	goto exit;
285
286	if (ret == size) {
287	memcpy(driver_data, data, size);
288	ret = 0;
289	} else {
290	ret = -EREMOTEIO;
291	}
292
293	exit:
294	kfree(objp: data);
295	return ret;
296	}
297	EXPORT_SYMBOL_GPL(usb_control_msg_recv);
298
299	/**
300	* usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
301	* @usb_dev: pointer to the usb device to send the message to
302	* @pipe: endpoint "pipe" to send the message to
303	* @data: pointer to the data to send
304	* @len: length in bytes of the data to send
305	* @actual_length: pointer to a location to put the actual length transferred
306	* in bytes
307	* @timeout: time in msecs to wait for the message to complete before
308	* timing out (if 0 the wait is forever)
309	*
310	* Context: task context, might sleep.
311	*
312	* This function sends a simple interrupt message to a specified endpoint and
313	* waits for the message to complete, or timeout.
314	*
315	* Don't use this function from within an interrupt context. If you need
316	* an asynchronous message, or need to send a message from within interrupt
317	* context, use usb_submit_urb() If a thread in your driver uses this call,
318	* make sure your disconnect() method can wait for it to complete. Since you
319	* don't have a handle on the URB used, you can't cancel the request.
320	*
321	* Return:
322	* If successful, 0. Otherwise a negative error number. The number of actual
323	* bytes transferred will be stored in the @actual_length parameter.
324	*/
325	int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
326	void *data, int len, int *actual_length, int timeout)
327	{
328	return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
329	}
330	EXPORT_SYMBOL_GPL(usb_interrupt_msg);
331
332	/**
333	* usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
334	* @usb_dev: pointer to the usb device to send the message to
335	* @pipe: endpoint "pipe" to send the message to
336	* @data: pointer to the data to send
337	* @len: length in bytes of the data to send
338	* @actual_length: pointer to a location to put the actual length transferred
339	* in bytes
340	* @timeout: time in msecs to wait for the message to complete before
341	* timing out (if 0 the wait is forever)
342	*
343	* Context: task context, might sleep.
344	*
345	* This function sends a simple bulk message to a specified endpoint
346	* and waits for the message to complete, or timeout.
347	*
348	* Don't use this function from within an interrupt context. If you need
349	* an asynchronous message, or need to send a message from within interrupt
350	* context, use usb_submit_urb() If a thread in your driver uses this call,
351	* make sure your disconnect() method can wait for it to complete. Since you
352	* don't have a handle on the URB used, you can't cancel the request.
353	*
354	* Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
355	* users are forced to abuse this routine by using it to submit URBs for
356	* interrupt endpoints. We will take the liberty of creating an interrupt URB
357	* (with the default interval) if the target is an interrupt endpoint.
358	*
359	* Return:
360	* If successful, 0. Otherwise a negative error number. The number of actual
361	* bytes transferred will be stored in the @actual_length parameter.
362	*
363	*/
364	int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
365	void *data, int len, int *actual_length, int timeout)
366	{
367	struct urb *urb;
368	struct usb_host_endpoint *ep;
369
370	ep = usb_pipe_endpoint(dev: usb_dev, pipe);
371	if (!ep || len < 0)
372	return -EINVAL;
373
374	urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
375	if (!urb)
376	return -ENOMEM;
377
378	if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
379	USB_ENDPOINT_XFER_INT) {
380	pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
381	usb_fill_int_urb(urb, dev: usb_dev, pipe, transfer_buffer: data, buffer_length: len,
382	complete_fn: usb_api_blocking_completion, NULL,
383	interval: ep->desc.bInterval);
384	} else
385	usb_fill_bulk_urb(urb, dev: usb_dev, pipe, transfer_buffer: data, buffer_length: len,
386	complete_fn: usb_api_blocking_completion, NULL);
387
388	return usb_start_wait_urb(urb, timeout, actual_length);
389	}
390	EXPORT_SYMBOL_GPL(usb_bulk_msg);
391
392	/*-------------------------------------------------------------------*/
393
394	static void sg_clean(struct usb_sg_request *io)
395	{
396	if (io->urbs) {
397	while (io->entries--)
398	usb_free_urb(urb: io->urbs[io->entries]);
399	kfree(objp: io->urbs);
400	io->urbs = NULL;
401	}
402	io->dev = NULL;
403	}
404
405	static void sg_complete(struct urb *urb)
406	{
407	unsigned long flags;
408	struct usb_sg_request *io = urb->context;
409	int status = urb->status;
410
411	spin_lock_irqsave(&io->lock, flags);
412
413	/* In 2.5 we require hcds' endpoint queues not to progress after fault
414	* reports, until the completion callback (this!) returns. That lets
415	* device driver code (like this routine) unlink queued urbs first,
416	* if it needs to, since the HC won't work on them at all. So it's
417	* not possible for page N+1 to overwrite page N, and so on.
418	*
419	* That's only for "hard" faults; "soft" faults (unlinks) sometimes
420	* complete before the HCD can get requests away from hardware,
421	* though never during cleanup after a hard fault.
422	*/
423	if (io->status
424	&& (io->status != -ECONNRESET
425	|| status != -ECONNRESET)
426	&& urb->actual_length) {
427	dev_err(io->dev->bus->controller,
428	"dev %s ep%d%s scatterlist error %d/%d\n",
429	io->dev->devpath,
430	usb_endpoint_num(&urb->ep->desc),
431	usb_urb_dir_in(urb) ? "in" : "out",
432	status, io->status);
433	/* BUG (); */
434	}
435
436	if (io->status == 0 && status && status != -ECONNRESET) {
437	int i, found, retval;
438
439	io->status = status;
440
441	/* the previous urbs, and this one, completed already.
442	* unlink pending urbs so they won't rx/tx bad data.
443	* careful: unlink can sometimes be synchronous...
444	*/
445	spin_unlock_irqrestore(lock: &io->lock, flags);
446	for (i = 0, found = 0; i < io->entries; i++) {
447	if (!io->urbs[i])
448	continue;
449	if (found) {
450	usb_block_urb(urb: io->urbs[i]);
451	retval = usb_unlink_urb(urb: io->urbs[i]);
452	if (retval != -EINPROGRESS &&
453	retval != -ENODEV &&
454	retval != -EBUSY &&
455	retval != -EIDRM)
456	dev_err(&io->dev->dev,
457	"%s, unlink --> %d\n",
458	__func__, retval);
459	} else if (urb == io->urbs[i])
460	found = 1;
461	}
462	spin_lock_irqsave(&io->lock, flags);
463	}
464
465	/* on the last completion, signal usb_sg_wait() */
466	io->bytes += urb->actual_length;
467	io->count--;
468	if (!io->count)
469	complete(&io->complete);
470
471	spin_unlock_irqrestore(lock: &io->lock, flags);
472	}
473
474
475	/**
476	* usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
477	* @io: request block being initialized. until usb_sg_wait() returns,
478	* treat this as a pointer to an opaque block of memory,
479	* @dev: the usb device that will send or receive the data
480	* @pipe: endpoint "pipe" used to transfer the data
481	* @period: polling rate for interrupt endpoints, in frames or
482	* (for high speed endpoints) microframes; ignored for bulk
483	* @sg: scatterlist entries
484	* @nents: how many entries in the scatterlist
485	* @length: how many bytes to send from the scatterlist, or zero to
486	* send every byte identified in the list.
487	* @mem_flags: SLAB_* flags affecting memory allocations in this call
488	*
489	* This initializes a scatter/gather request, allocating resources such as
490	* I/O mappings and urb memory (except maybe memory used by USB controller
491	* drivers).
492	*
493	* The request must be issued using usb_sg_wait(), which waits for the I/O to
494	* complete (or to be canceled) and then cleans up all resources allocated by
495	* usb_sg_init().
496	*
497	* The request may be canceled with usb_sg_cancel(), either before or after
498	* usb_sg_wait() is called.
499	*
500	* Return: Zero for success, else a negative errno value.
501	*/
502	int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
503	unsigned pipe, unsigned period, struct scatterlist *sg,
504	int nents, size_t length, gfp_t mem_flags)
505	{
506	int i;
507	int urb_flags;
508	int use_sg;
509
510	if (!io || !dev || !sg
511	|| usb_pipecontrol(pipe)
512	|| usb_pipeisoc(pipe)
513	|| nents <= 0)
514	return -EINVAL;
515
516	spin_lock_init(&io->lock);
517	io->dev = dev;
518	io->pipe = pipe;
519
520	if (dev->bus->sg_tablesize > 0) {
521	use_sg = true;
522	io->entries = 1;
523	} else {
524	use_sg = false;
525	io->entries = nents;
526	}
527
528	/* initialize all the urbs we'll use */
529	io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
530	if (!io->urbs)
531	goto nomem;
532
533	urb_flags = URB_NO_INTERRUPT;
534	if (usb_pipein(pipe))
535	urb_flags |= URB_SHORT_NOT_OK;
536
537	for_each_sg(sg, sg, io->entries, i) {
538	struct urb *urb;
539	unsigned len;
540
541	urb = usb_alloc_urb(iso_packets: 0, mem_flags);
542	if (!urb) {
543	io->entries = i;
544	goto nomem;
545	}
546	io->urbs[i] = urb;
547
548	urb->dev = NULL;
549	urb->pipe = pipe;
550	urb->interval = period;
551	urb->transfer_flags = urb_flags;
552	urb->complete = sg_complete;
553	urb->context = io;
554	urb->sg = sg;
555
556	if (use_sg) {
557	/* There is no single transfer buffer */
558	urb->transfer_buffer = NULL;
559	urb->num_sgs = nents;
560
561	/* A length of zero means transfer the whole sg list */
562	len = length;
563	if (len == 0) {
564	struct scatterlist *sg2;
565	int j;
566
567	for_each_sg(sg, sg2, nents, j)
568	len += sg2->length;
569	}
570	} else {
571	/*
572	* Some systems can't use DMA; they use PIO instead.
573	* For their sakes, transfer_buffer is set whenever
574	* possible.
575	*/
576	if (!PageHighMem(page: sg_page(sg)))
577	urb->transfer_buffer = sg_virt(sg);
578	else
579	urb->transfer_buffer = NULL;
580
581	len = sg->length;
582	if (length) {
583	len = min_t(size_t, len, length);
584	length -= len;
585	if (length == 0)
586	io->entries = i + 1;
587	}
588	}
589	urb->transfer_buffer_length = len;
590	}
591	io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
592
593	/* transaction state */
594	io->count = io->entries;
595	io->status = 0;
596	io->bytes = 0;
597	init_completion(x: &io->complete);
598	return 0;
599
600	nomem:
601	sg_clean(io);
602	return -ENOMEM;
603	}
604	EXPORT_SYMBOL_GPL(usb_sg_init);
605
606	/**
607	* usb_sg_wait - synchronously execute scatter/gather request
608	* @io: request block handle, as initialized with usb_sg_init().
609	* some fields become accessible when this call returns.
610	*
611	* Context: task context, might sleep.
612	*
613	* This function blocks until the specified I/O operation completes. It
614	* leverages the grouping of the related I/O requests to get good transfer
615	* rates, by queueing the requests. At higher speeds, such queuing can
616	* significantly improve USB throughput.
617	*
618	* There are three kinds of completion for this function.
619	*
620	* (1) success, where io->status is zero. The number of io->bytes
621	* transferred is as requested.
622	* (2) error, where io->status is a negative errno value. The number
623	* of io->bytes transferred before the error is usually less
624	* than requested, and can be nonzero.
625	* (3) cancellation, a type of error with status -ECONNRESET that
626	* is initiated by usb_sg_cancel().
627	*
628	* When this function returns, all memory allocated through usb_sg_init() or
629	* this call will have been freed. The request block parameter may still be
630	* passed to usb_sg_cancel(), or it may be freed. It could also be
631	* reinitialized and then reused.
632	*
633	* Data Transfer Rates:
634	*
635	* Bulk transfers are valid for full or high speed endpoints.
636	* The best full speed data rate is 19 packets of 64 bytes each
637	* per frame, or 1216 bytes per millisecond.
638	* The best high speed data rate is 13 packets of 512 bytes each
639	* per microframe, or 52 KBytes per millisecond.
640	*
641	* The reason to use interrupt transfers through this API would most likely
642	* be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
643	* could be transferred. That capability is less useful for low or full
644	* speed interrupt endpoints, which allow at most one packet per millisecond,
645	* of at most 8 or 64 bytes (respectively).
646	*
647	* It is not necessary to call this function to reserve bandwidth for devices
648	* under an xHCI host controller, as the bandwidth is reserved when the
649	* configuration or interface alt setting is selected.
650	*/
651	void usb_sg_wait(struct usb_sg_request *io)
652	{
653	int i;
654	int entries = io->entries;
655
656	/* queue the urbs. */
657	spin_lock_irq(lock: &io->lock);
658	i = 0;
659	while (i < entries && !io->status) {
660	int retval;
661
662	io->urbs[i]->dev = io->dev;
663	spin_unlock_irq(lock: &io->lock);
664
665	retval = usb_submit_urb(urb: io->urbs[i], GFP_NOIO);
666
667	switch (retval) {
668	/* maybe we retrying will recover */
669	case -ENXIO: /* hc didn't queue this one */
670	case -EAGAIN:
671	case -ENOMEM:
672	retval = 0;
673	yield();
674	break;
675
676	/* no error? continue immediately.
677	*
678	* NOTE: to work better with UHCI (4K I/O buffer may
679	* need 3K of TDs) it may be good to limit how many
680	* URBs are queued at once; N milliseconds?
681	*/
682	case 0:
683	++i;
684	cpu_relax();
685	break;
686
687	/* fail any uncompleted urbs */
688	default:
689	io->urbs[i]->status = retval;
690	dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
691	__func__, retval);
692	usb_sg_cancel(io);
693	}
694	spin_lock_irq(lock: &io->lock);
695	if (retval && (io->status == 0 || io->status == -ECONNRESET))
696	io->status = retval;
697	}
698	io->count -= entries - i;
699	if (io->count == 0)
700	complete(&io->complete);
701	spin_unlock_irq(lock: &io->lock);
702
703	/* OK, yes, this could be packaged as non-blocking.
704	* So could the submit loop above ... but it's easier to
705	* solve neither problem than to solve both!
706	*/
707	wait_for_completion(&io->complete);
708
709	sg_clean(io);
710	}
711	EXPORT_SYMBOL_GPL(usb_sg_wait);
712
713	/**
714	* usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
715	* @io: request block, initialized with usb_sg_init()
716	*
717	* This stops a request after it has been started by usb_sg_wait().
718	* It can also prevents one initialized by usb_sg_init() from starting,
719	* so that call just frees resources allocated to the request.
720	*/
721	void usb_sg_cancel(struct usb_sg_request *io)
722	{
723	unsigned long flags;
724	int i, retval;
725
726	spin_lock_irqsave(&io->lock, flags);
727	if (io->status || io->count == 0) {
728	spin_unlock_irqrestore(lock: &io->lock, flags);
729	return;
730	}
731	/* shut everything down */
732	io->status = -ECONNRESET;
733	io->count++; /* Keep the request alive until we're done */
734	spin_unlock_irqrestore(lock: &io->lock, flags);
735
736	for (i = io->entries - 1; i >= 0; --i) {
737	usb_block_urb(urb: io->urbs[i]);
738
739	retval = usb_unlink_urb(urb: io->urbs[i]);
740	if (retval != -EINPROGRESS
741	&& retval != -ENODEV
742	&& retval != -EBUSY
743	&& retval != -EIDRM)
744	dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
745	__func__, retval);
746	}
747
748	spin_lock_irqsave(&io->lock, flags);
749	io->count--;
750	if (!io->count)
751	complete(&io->complete);
752	spin_unlock_irqrestore(lock: &io->lock, flags);
753	}
754	EXPORT_SYMBOL_GPL(usb_sg_cancel);
755
756	/*-------------------------------------------------------------------*/
757
758	/**
759	* usb_get_descriptor - issues a generic GET_DESCRIPTOR request
760	* @dev: the device whose descriptor is being retrieved
761	* @type: the descriptor type (USB_DT_*)
762	* @index: the number of the descriptor
763	* @buf: where to put the descriptor
764	* @size: how big is "buf"?
765	*
766	* Context: task context, might sleep.
767	*
768	* Gets a USB descriptor. Convenience functions exist to simplify
769	* getting some types of descriptors. Use
770	* usb_get_string() or usb_string() for USB_DT_STRING.
771	* Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
772	* are part of the device structure.
773	* In addition to a number of USB-standard descriptors, some
774	* devices also use class-specific or vendor-specific descriptors.
775	*
776	* This call is synchronous, and may not be used in an interrupt context.
777	*
778	* Return: The number of bytes received on success, or else the status code
779	* returned by the underlying usb_control_msg() call.
780	*/
781	int usb_get_descriptor(struct usb_device *dev, unsigned char type,
782	unsigned char index, void *buf, int size)
783	{
784	int i;
785	int result;
786
787	if (size <= 0) /* No point in asking for no data */
788	return -EINVAL;
789
790	memset(buf, 0, size); /* Make sure we parse really received data */
791
792	for (i = 0; i < 3; ++i) {
793	/* retry on length 0 or error; some devices are flakey */
794	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
795	USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
796	(type << 8) + index, 0, buf, size,
797	USB_CTRL_GET_TIMEOUT);
798	if (result <= 0 && result != -ETIMEDOUT)
799	continue;
800	if (result > 1 && ((u8 *)buf)[1] != type) {
801	result = -ENODATA;
802	continue;
803	}
804	break;
805	}
806	return result;
807	}
808	EXPORT_SYMBOL_GPL(usb_get_descriptor);
809
810	/**
811	* usb_get_string - gets a string descriptor
812	* @dev: the device whose string descriptor is being retrieved
813	* @langid: code for language chosen (from string descriptor zero)
814	* @index: the number of the descriptor
815	* @buf: where to put the string
816	* @size: how big is "buf"?
817	*
818	* Context: task context, might sleep.
819	*
820	* Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
821	* in little-endian byte order).
822	* The usb_string() function will often be a convenient way to turn
823	* these strings into kernel-printable form.
824	*
825	* Strings may be referenced in device, configuration, interface, or other
826	* descriptors, and could also be used in vendor-specific ways.
827	*
828	* This call is synchronous, and may not be used in an interrupt context.
829	*
830	* Return: The number of bytes received on success, or else the status code
831	* returned by the underlying usb_control_msg() call.
832	*/
833	static int usb_get_string(struct usb_device *dev, unsigned short langid,
834	unsigned char index, void *buf, int size)
835	{
836	int i;
837	int result;
838
839	if (size <= 0) /* No point in asking for no data */
840	return -EINVAL;
841
842	for (i = 0; i < 3; ++i) {
843	/* retry on length 0 or stall; some devices are flakey */
844	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
845	USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
846	(USB_DT_STRING << 8) + index, langid, buf, size,
847	USB_CTRL_GET_TIMEOUT);
848	if (result == 0 || result == -EPIPE)
849	continue;
850	if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
851	result = -ENODATA;
852	continue;
853	}
854	break;
855	}
856	return result;
857	}
858
859	static void usb_try_string_workarounds(unsigned char *buf, int *length)
860	{
861	int newlength, oldlength = *length;
862
863	for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
864	if (!isprint(buf[newlength]) || buf[newlength + 1])
865	break;
866
867	if (newlength > 2) {
868	buf[0] = newlength;
869	*length = newlength;
870	}
871	}
872
873	static int usb_string_sub(struct usb_device *dev, unsigned int langid,
874	unsigned int index, unsigned char *buf)
875	{
876	int rc;
877
878	/* Try to read the string descriptor by asking for the maximum
879	* possible number of bytes */
880	if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
881	rc = -EIO;
882	else
883	rc = usb_get_string(dev, langid, index, buf, size: 255);
884
885	/* If that failed try to read the descriptor length, then
886	* ask for just that many bytes */
887	if (rc < 2) {
888	rc = usb_get_string(dev, langid, index, buf, size: 2);
889	if (rc == 2)
890	rc = usb_get_string(dev, langid, index, buf, size: buf[0]);
891	}
892
893	if (rc >= 2) {
894	if (!buf[0] && !buf[1])
895	usb_try_string_workarounds(buf, length: &rc);
896
897	/* There might be extra junk at the end of the descriptor */
898	if (buf[0] < rc)
899	rc = buf[0];
900
901	rc = rc - (rc & 1); /* force a multiple of two */
902	}
903
904	if (rc < 2)
905	rc = (rc < 0 ? rc : -EINVAL);
906
907	return rc;
908	}
909
910	static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
911	{
912	int err;
913
914	if (dev->have_langid)
915	return 0;
916
917	if (dev->string_langid < 0)
918	return -EPIPE;
919
920	err = usb_string_sub(dev, langid: 0, index: 0, buf: tbuf);
921
922	/* If the string was reported but is malformed, default to english
923	* (0x0409) */
924	if (err == -ENODATA || (err > 0 && err < 4)) {
925	dev->string_langid = 0x0409;
926	dev->have_langid = 1;
927	dev_err(&dev->dev,
928	"language id specifier not provided by device, defaulting to English\n");
929	return 0;
930	}
931
932	/* In case of all other errors, we assume the device is not able to
933	* deal with strings at all. Set string_langid to -1 in order to
934	* prevent any string to be retrieved from the device */
935	if (err < 0) {
936	dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
937	err);
938	dev->string_langid = -1;
939	return -EPIPE;
940	}
941
942	/* always use the first langid listed */
943	dev->string_langid = tbuf[2] | (tbuf[3] << 8);
944	dev->have_langid = 1;
945	dev_dbg(&dev->dev, "default language 0x%04x\n",
946	dev->string_langid);
947	return 0;
948	}
949
950	/**
951	* usb_string - returns UTF-8 version of a string descriptor
952	* @dev: the device whose string descriptor is being retrieved
953	* @index: the number of the descriptor
954	* @buf: where to put the string
955	* @size: how big is "buf"?
956	*
957	* Context: task context, might sleep.
958	*
959	* This converts the UTF-16LE encoded strings returned by devices, from
960	* usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
961	* that are more usable in most kernel contexts. Note that this function
962	* chooses strings in the first language supported by the device.
963	*
964	* This call is synchronous, and may not be used in an interrupt context.
965	*
966	* Return: length of the string (>= 0) or usb_control_msg status (< 0).
967	*/
968	int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
969	{
970	unsigned char *tbuf;
971	int err;
972
973	if (dev->state == USB_STATE_SUSPENDED)
974	return -EHOSTUNREACH;
975	if (size <= 0 || !buf)
976	return -EINVAL;
977	buf[0] = 0;
978	if (index <= 0 || index >= 256)
979	return -EINVAL;
980	tbuf = kmalloc(256, GFP_NOIO);
981	if (!tbuf)
982	return -ENOMEM;
983
984	err = usb_get_langid(dev, tbuf);
985	if (err < 0)
986	goto errout;
987
988	err = usb_string_sub(dev, langid: dev->string_langid, index, buf: tbuf);
989	if (err < 0)
990	goto errout;
991
992	size--; /* leave room for trailing NULL char in output buffer */
993	err = utf16s_to_utf8s(pwcs: (wchar_t *) &tbuf[2], len: (err - 2) / 2,
994	endian: UTF16_LITTLE_ENDIAN, s: buf, maxlen: size);
995	buf[err] = 0;
996
997	if (tbuf[1] != USB_DT_STRING)
998	dev_dbg(&dev->dev,
999	"wrong descriptor type %02x for string %d (\"%s\")\n",
1000	tbuf[1], index, buf);
1001
1002	errout:
1003	kfree(objp: tbuf);
1004	return err;
1005	}
1006	EXPORT_SYMBOL_GPL(usb_string);
1007
1008	/* one UTF-8-encoded 16-bit character has at most three bytes */
1009	#define MAX_USB_STRING_SIZE (127 * 3 + 1)
1010
1011	/**
1012	* usb_cache_string - read a string descriptor and cache it for later use
1013	* @udev: the device whose string descriptor is being read
1014	* @index: the descriptor index
1015	*
1016	* Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
1017	* or %NULL if the index is 0 or the string could not be read.
1018	*/
1019	char *usb_cache_string(struct usb_device *udev, int index)
1020	{
1021	char *buf;
1022	char *smallbuf = NULL;
1023	int len;
1024
1025	if (index <= 0)
1026	return NULL;
1027
1028	buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
1029	if (buf) {
1030	len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
1031	if (len > 0) {
1032	smallbuf = kmalloc(++len, GFP_NOIO);
1033	if (!smallbuf)
1034	return buf;
1035	memcpy(smallbuf, buf, len);
1036	}
1037	kfree(objp: buf);
1038	}
1039	return smallbuf;
1040	}
1041	EXPORT_SYMBOL_GPL(usb_cache_string);
1042
1043	/*
1044	* usb_get_device_descriptor - read the device descriptor
1045	* @udev: the device whose device descriptor should be read
1046	*
1047	* Context: task context, might sleep.
1048	*
1049	* Not exported, only for use by the core. If drivers really want to read
1050	* the device descriptor directly, they can call usb_get_descriptor() with
1051	* type = USB_DT_DEVICE and index = 0.
1052	*
1053	* Returns: a pointer to a dynamically allocated usb_device_descriptor
1054	* structure (which the caller must deallocate), or an ERR_PTR value.
1055	*/
1056	struct usb_device_descriptor *usb_get_device_descriptor(struct usb_device *udev)
1057	{
1058	struct usb_device_descriptor *desc;
1059	int ret;
1060
1061	desc = kmalloc(sizeof(*desc), GFP_NOIO);
1062	if (!desc)
1063	return ERR_PTR(error: -ENOMEM);
1064
1065	ret = usb_get_descriptor(udev, USB_DT_DEVICE, 0, desc, sizeof(*desc));
1066	if (ret == sizeof(*desc))
1067	return desc;
1068
1069	if (ret >= 0)
1070	ret = -EMSGSIZE;
1071	kfree(objp: desc);
1072	return ERR_PTR(error: ret);
1073	}
1074
1075	/*
1076	* usb_set_isoch_delay - informs the device of the packet transmit delay
1077	* @dev: the device whose delay is to be informed
1078	* Context: task context, might sleep
1079	*
1080	* Since this is an optional request, we don't bother if it fails.
1081	*/
1082	int usb_set_isoch_delay(struct usb_device *dev)
1083	{
1084	/* skip hub devices */
1085	if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
1086	return 0;
1087
1088	/* skip non-SS/non-SSP devices */
1089	if (dev->speed < USB_SPEED_SUPER)
1090	return 0;
1091
1092	return usb_control_msg_send(dev, 0,
1093	USB_REQ_SET_ISOCH_DELAY,
1094	USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1095	dev->hub_delay, 0, NULL, 0,
1096	USB_CTRL_SET_TIMEOUT,
1097	GFP_NOIO);
1098	}
1099
1100	/**
1101	* usb_get_status - issues a GET_STATUS call
1102	* @dev: the device whose status is being checked
1103	* @recip: USB_RECIP_*; for device, interface, or endpoint
1104	* @type: USB_STATUS_TYPE_*; for standard or PTM status types
1105	* @target: zero (for device), else interface or endpoint number
1106	* @data: pointer to two bytes of bitmap data
1107	*
1108	* Context: task context, might sleep.
1109	*
1110	* Returns device, interface, or endpoint status. Normally only of
1111	* interest to see if the device is self powered, or has enabled the
1112	* remote wakeup facility; or whether a bulk or interrupt endpoint
1113	* is halted ("stalled").
1114	*
1115	* Bits in these status bitmaps are set using the SET_FEATURE request,
1116	* and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
1117	* function should be used to clear halt ("stall") status.
1118	*
1119	* This call is synchronous, and may not be used in an interrupt context.
1120	*
1121	* Returns 0 and the status value in *@data (in host byte order) on success,
1122	* or else the status code from the underlying usb_control_msg() call.
1123	*/
1124	int usb_get_status(struct usb_device *dev, int recip, int type, int target,
1125	void *data)
1126	{
1127	int ret;
1128	void *status;
1129	int length;
1130
1131	switch (type) {
1132	case USB_STATUS_TYPE_STANDARD:
1133	length = 2;
1134	break;
1135	case USB_STATUS_TYPE_PTM:
1136	if (recip != USB_RECIP_DEVICE)
1137	return -EINVAL;
1138
1139	length = 4;
1140	break;
1141	default:
1142	return -EINVAL;
1143	}
1144
1145	status = kmalloc(length, GFP_KERNEL);
1146	if (!status)
1147	return -ENOMEM;
1148
1149	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1150	USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1151	target, status, length, USB_CTRL_GET_TIMEOUT);
1152
1153	switch (ret) {
1154	case 4:
1155	if (type != USB_STATUS_TYPE_PTM) {
1156	ret = -EIO;
1157	break;
1158	}
1159
1160	*(u32 *) data = le32_to_cpu(*(__le32 *) status);
1161	ret = 0;
1162	break;
1163	case 2:
1164	if (type != USB_STATUS_TYPE_STANDARD) {
1165	ret = -EIO;
1166	break;
1167	}
1168
1169	*(u16 *) data = le16_to_cpu(*(__le16 *) status);
1170	ret = 0;
1171	break;
1172	default:
1173	ret = -EIO;
1174	}
1175
1176	kfree(objp: status);
1177	return ret;
1178	}
1179	EXPORT_SYMBOL_GPL(usb_get_status);
1180
1181	/**
1182	* usb_clear_halt - tells device to clear endpoint halt/stall condition
1183	* @dev: device whose endpoint is halted
1184	* @pipe: endpoint "pipe" being cleared
1185	*
1186	* Context: task context, might sleep.
1187	*
1188	* This is used to clear halt conditions for bulk and interrupt endpoints,
1189	* as reported by URB completion status. Endpoints that are halted are
1190	* sometimes referred to as being "stalled". Such endpoints are unable
1191	* to transmit or receive data until the halt status is cleared. Any URBs
1192	* queued for such an endpoint should normally be unlinked by the driver
1193	* before clearing the halt condition, as described in sections 5.7.5
1194	* and 5.8.5 of the USB 2.0 spec.
1195	*
1196	* Note that control and isochronous endpoints don't halt, although control
1197	* endpoints report "protocol stall" (for unsupported requests) using the
1198	* same status code used to report a true stall.
1199	*
1200	* This call is synchronous, and may not be used in an interrupt context.
1201	* If a thread in your driver uses this call, make sure your disconnect()
1202	* method can wait for it to complete.
1203	*
1204	* Return: Zero on success, or else the status code returned by the
1205	* underlying usb_control_msg() call.
1206	*/
1207	int usb_clear_halt(struct usb_device *dev, int pipe)
1208	{
1209	int result;
1210	int endp = usb_pipeendpoint(pipe);
1211
1212	if (usb_pipein(pipe))
1213	endp |= USB_DIR_IN;
1214
1215	/* we don't care if it wasn't halted first. in fact some devices
1216	* (like some ibmcam model 1 units) seem to expect hosts to make
1217	* this request for iso endpoints, which can't halt!
1218	*/
1219	result = usb_control_msg_send(dev, 0,
1220	USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1221	USB_ENDPOINT_HALT, endp, NULL, 0,
1222	USB_CTRL_SET_TIMEOUT, GFP_NOIO);
1223
1224	/* don't un-halt or force to DATA0 except on success */
1225	if (result)
1226	return result;
1227
1228	/* NOTE: seems like Microsoft and Apple don't bother verifying
1229	* the clear "took", so some devices could lock up if you check...
1230	* such as the Hagiwara FlashGate DUAL. So we won't bother.
1231	*
1232	* NOTE: make sure the logic here doesn't diverge much from
1233	* the copy in usb-storage, for as long as we need two copies.
1234	*/
1235
1236	usb_reset_endpoint(dev, epaddr: endp);
1237
1238	return 0;
1239	}
1240	EXPORT_SYMBOL_GPL(usb_clear_halt);
1241
1242	static int create_intf_ep_devs(struct usb_interface *intf)
1243	{
1244	struct usb_device *udev = interface_to_usbdev(intf);
1245	struct usb_host_interface *alt = intf->cur_altsetting;
1246	int i;
1247
1248	if (intf->ep_devs_created || intf->unregistering)
1249	return 0;
1250
1251	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1252	(void) usb_create_ep_devs(parent: &intf->dev, endpoint: &alt->endpoint[i], udev);
1253	intf->ep_devs_created = 1;
1254	return 0;
1255	}
1256
1257	static void remove_intf_ep_devs(struct usb_interface *intf)
1258	{
1259	struct usb_host_interface *alt = intf->cur_altsetting;
1260	int i;
1261
1262	if (!intf->ep_devs_created)
1263	return;
1264
1265	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1266	usb_remove_ep_devs(endpoint: &alt->endpoint[i]);
1267	intf->ep_devs_created = 0;
1268	}
1269
1270	/**
1271	* usb_disable_endpoint -- Disable an endpoint by address
1272	* @dev: the device whose endpoint is being disabled
1273	* @epaddr: the endpoint's address. Endpoint number for output,
1274	* endpoint number + USB_DIR_IN for input
1275	* @reset_hardware: flag to erase any endpoint state stored in the
1276	* controller hardware
1277	*
1278	* Disables the endpoint for URB submission and nukes all pending URBs.
1279	* If @reset_hardware is set then also deallocates hcd/hardware state
1280	* for the endpoint.
1281	*/
1282	void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1283	bool reset_hardware)
1284	{
1285	unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1286	struct usb_host_endpoint *ep;
1287
1288	if (!dev)
1289	return;
1290
1291	if (usb_endpoint_out(epaddr)) {
1292	ep = dev->ep_out[epnum];
1293	if (reset_hardware && epnum != 0)
1294	dev->ep_out[epnum] = NULL;
1295	} else {
1296	ep = dev->ep_in[epnum];
1297	if (reset_hardware && epnum != 0)
1298	dev->ep_in[epnum] = NULL;
1299	}
1300	if (ep) {
1301	ep->enabled = 0;
1302	usb_hcd_flush_endpoint(udev: dev, ep);
1303	if (reset_hardware)
1304	usb_hcd_disable_endpoint(udev: dev, ep);
1305	}
1306	}
1307
1308	/**
1309	* usb_reset_endpoint - Reset an endpoint's state.
1310	* @dev: the device whose endpoint is to be reset
1311	* @epaddr: the endpoint's address. Endpoint number for output,
1312	* endpoint number + USB_DIR_IN for input
1313	*
1314	* Resets any host-side endpoint state such as the toggle bit,
1315	* sequence number or current window.
1316	*/
1317	void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1318	{
1319	unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1320	struct usb_host_endpoint *ep;
1321
1322	if (usb_endpoint_out(epaddr))
1323	ep = dev->ep_out[epnum];
1324	else
1325	ep = dev->ep_in[epnum];
1326	if (ep)
1327	usb_hcd_reset_endpoint(udev: dev, ep);
1328	}
1329	EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1330
1331
1332	/**
1333	* usb_disable_interface -- Disable all endpoints for an interface
1334	* @dev: the device whose interface is being disabled
1335	* @intf: pointer to the interface descriptor
1336	* @reset_hardware: flag to erase any endpoint state stored in the
1337	* controller hardware
1338	*
1339	* Disables all the endpoints for the interface's current altsetting.
1340	*/
1341	void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1342	bool reset_hardware)
1343	{
1344	struct usb_host_interface *alt = intf->cur_altsetting;
1345	int i;
1346
1347	for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1348	usb_disable_endpoint(dev,
1349	epaddr: alt->endpoint[i].desc.bEndpointAddress,
1350	reset_hardware);
1351	}
1352	}
1353
1354	/*
1355	* usb_disable_device_endpoints -- Disable all endpoints for a device
1356	* @dev: the device whose endpoints are being disabled
1357	* @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1358	*/
1359	static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1360	{
1361	struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
1362	int i;
1363
1364	if (hcd->driver->check_bandwidth) {
1365	/* First pass: Cancel URBs, leave endpoint pointers intact. */
1366	for (i = skip_ep0; i < 16; ++i) {
1367	usb_disable_endpoint(dev, epaddr: i, reset_hardware: false);
1368	usb_disable_endpoint(dev, epaddr: i + USB_DIR_IN, reset_hardware: false);
1369	}
1370	/* Remove endpoints from the host controller internal state */
1371	mutex_lock(hcd->bandwidth_mutex);
1372	usb_hcd_alloc_bandwidth(udev: dev, NULL, NULL, NULL);
1373	mutex_unlock(lock: hcd->bandwidth_mutex);
1374	}
1375	/* Second pass: remove endpoint pointers */
1376	for (i = skip_ep0; i < 16; ++i) {
1377	usb_disable_endpoint(dev, epaddr: i, reset_hardware: true);
1378	usb_disable_endpoint(dev, epaddr: i + USB_DIR_IN, reset_hardware: true);
1379	}
1380	}
1381
1382	/**
1383	* usb_disable_device - Disable all the endpoints for a USB device
1384	* @dev: the device whose endpoints are being disabled
1385	* @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1386	*
1387	* Disables all the device's endpoints, potentially including endpoint 0.
1388	* Deallocates hcd/hardware state for the endpoints (nuking all or most
1389	* pending urbs) and usbcore state for the interfaces, so that usbcore
1390	* must usb_set_configuration() before any interfaces could be used.
1391	*/
1392	void usb_disable_device(struct usb_device *dev, int skip_ep0)
1393	{
1394	int i;
1395
1396	/* getting rid of interfaces will disconnect
1397	* any drivers bound to them (a key side effect)
1398	*/
1399	if (dev->actconfig) {
1400	/*
1401	* FIXME: In order to avoid self-deadlock involving the
1402	* bandwidth_mutex, we have to mark all the interfaces
1403	* before unregistering any of them.
1404	*/
1405	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1406	dev->actconfig->interface[i]->unregistering = 1;
1407
1408	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1409	struct usb_interface *interface;
1410
1411	/* remove this interface if it has been registered */
1412	interface = dev->actconfig->interface[i];
1413	if (!device_is_registered(dev: &interface->dev))
1414	continue;
1415	dev_dbg(&dev->dev, "unregistering interface %s\n",
1416	dev_name(&interface->dev));
1417	remove_intf_ep_devs(intf: interface);
1418	device_del(dev: &interface->dev);
1419	}
1420
1421	/* Now that the interfaces are unbound, nobody should
1422	* try to access them.
1423	*/
1424	for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1425	put_device(dev: &dev->actconfig->interface[i]->dev);
1426	dev->actconfig->interface[i] = NULL;
1427	}
1428
1429	usb_disable_usb2_hardware_lpm(udev: dev);
1430	usb_unlocked_disable_lpm(udev: dev);
1431	usb_disable_ltm(udev: dev);
1432
1433	dev->actconfig = NULL;
1434	if (dev->state == USB_STATE_CONFIGURED)
1435	usb_set_device_state(udev: dev, new_state: USB_STATE_ADDRESS);
1436	}
1437
1438	dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1439	skip_ep0 ? "non-ep0" : "all");
1440
1441	usb_disable_device_endpoints(dev, skip_ep0);
1442	}
1443
1444	/**
1445	* usb_enable_endpoint - Enable an endpoint for USB communications
1446	* @dev: the device whose interface is being enabled
1447	* @ep: the endpoint
1448	* @reset_ep: flag to reset the endpoint state
1449	*
1450	* Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1451	* For control endpoints, both the input and output sides are handled.
1452	*/
1453	void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1454	bool reset_ep)
1455	{
1456	int epnum = usb_endpoint_num(epd: &ep->desc);
1457	int is_out = usb_endpoint_dir_out(epd: &ep->desc);
1458	int is_control = usb_endpoint_xfer_control(epd: &ep->desc);
1459
1460	if (reset_ep)
1461	usb_hcd_reset_endpoint(udev: dev, ep);
1462	if (is_out || is_control)
1463	dev->ep_out[epnum] = ep;
1464	if (!is_out || is_control)
1465	dev->ep_in[epnum] = ep;
1466	ep->enabled = 1;
1467	}
1468
1469	/**
1470	* usb_enable_interface - Enable all the endpoints for an interface
1471	* @dev: the device whose interface is being enabled
1472	* @intf: pointer to the interface descriptor
1473	* @reset_eps: flag to reset the endpoints' state
1474	*
1475	* Enables all the endpoints for the interface's current altsetting.
1476	*/
1477	void usb_enable_interface(struct usb_device *dev,
1478	struct usb_interface *intf, bool reset_eps)
1479	{
1480	struct usb_host_interface *alt = intf->cur_altsetting;
1481	int i;
1482
1483	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1484	usb_enable_endpoint(dev, ep: &alt->endpoint[i], reset_ep: reset_eps);
1485	}
1486
1487	/**
1488	* usb_set_interface - Makes a particular alternate setting be current
1489	* @dev: the device whose interface is being updated
1490	* @interface: the interface being updated
1491	* @alternate: the setting being chosen.
1492	*
1493	* Context: task context, might sleep.
1494	*
1495	* This is used to enable data transfers on interfaces that may not
1496	* be enabled by default. Not all devices support such configurability.
1497	* Only the driver bound to an interface may change its setting.
1498	*
1499	* Within any given configuration, each interface may have several
1500	* alternative settings. These are often used to control levels of
1501	* bandwidth consumption. For example, the default setting for a high
1502	* speed interrupt endpoint may not send more than 64 bytes per microframe,
1503	* while interrupt transfers of up to 3KBytes per microframe are legal.
1504	* Also, isochronous endpoints may never be part of an
1505	* interface's default setting. To access such bandwidth, alternate
1506	* interface settings must be made current.
1507	*
1508	* Note that in the Linux USB subsystem, bandwidth associated with
1509	* an endpoint in a given alternate setting is not reserved until an URB
1510	* is submitted that needs that bandwidth. Some other operating systems
1511	* allocate bandwidth early, when a configuration is chosen.
1512	*
1513	* xHCI reserves bandwidth and configures the alternate setting in
1514	* usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1515	* may be disabled. Drivers cannot rely on any particular alternate
1516	* setting being in effect after a failure.
1517	*
1518	* This call is synchronous, and may not be used in an interrupt context.
1519	* Also, drivers must not change altsettings while urbs are scheduled for
1520	* endpoints in that interface; all such urbs must first be completed
1521	* (perhaps forced by unlinking). If a thread in your driver uses this call,
1522	* make sure your disconnect() method can wait for it to complete.
1523	*
1524	* Return: Zero on success, or else the status code returned by the
1525	* underlying usb_control_msg() call.
1526	*/
1527	int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1528	{
1529	struct usb_interface *iface;
1530	struct usb_host_interface *alt;
1531	struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
1532	int i, ret, manual = 0;
1533	unsigned int epaddr;
1534	unsigned int pipe;
1535
1536	if (dev->state == USB_STATE_SUSPENDED)
1537	return -EHOSTUNREACH;
1538
1539	iface = usb_ifnum_to_if(dev, ifnum: interface);
1540	if (!iface) {
1541	dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1542	interface);
1543	return -EINVAL;
1544	}
1545	if (iface->unregistering)
1546	return -ENODEV;
1547
1548	alt = usb_altnum_to_altsetting(intf: iface, altnum: alternate);
1549	if (!alt) {
1550	dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1551	alternate);
1552	return -EINVAL;
1553	}
1554	/*
1555	* usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1556	* including freeing dropped endpoint ring buffers.
1557	* Make sure the interface endpoints are flushed before that
1558	*/
1559	usb_disable_interface(dev, intf: iface, reset_hardware: false);
1560
1561	/* Make sure we have enough bandwidth for this alternate interface.
1562	* Remove the current alt setting and add the new alt setting.
1563	*/
1564	mutex_lock(hcd->bandwidth_mutex);
1565	/* Disable LPM, and re-enable it once the new alt setting is installed,
1566	* so that the xHCI driver can recalculate the U1/U2 timeouts.
1567	*/
1568	if (usb_disable_lpm(udev: dev)) {
1569	dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1570	mutex_unlock(lock: hcd->bandwidth_mutex);
1571	return -ENOMEM;
1572	}
1573	/* Changing alt-setting also frees any allocated streams */
1574	for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1575	iface->cur_altsetting->endpoint[i].streams = 0;
1576
1577	ret = usb_hcd_alloc_bandwidth(udev: dev, NULL, old_alt: iface->cur_altsetting, new_alt: alt);
1578	if (ret < 0) {
1579	dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1580	alternate);
1581	usb_enable_lpm(udev: dev);
1582	mutex_unlock(lock: hcd->bandwidth_mutex);
1583	return ret;
1584	}
1585
1586	if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1587	ret = -EPIPE;
1588	else
1589	ret = usb_control_msg_send(dev, 0,
1590	USB_REQ_SET_INTERFACE,
1591	USB_RECIP_INTERFACE, alternate,
1592	interface, NULL, 0, 5000,
1593	GFP_NOIO);
1594
1595	/* 9.4.10 says devices don't need this and are free to STALL the
1596	* request if the interface only has one alternate setting.
1597	*/
1598	if (ret == -EPIPE && iface->num_altsetting == 1) {
1599	dev_dbg(&dev->dev,
1600	"manual set_interface for iface %d, alt %d\n",
1601	interface, alternate);
1602	manual = 1;
1603	} else if (ret) {
1604	/* Re-instate the old alt setting */
1605	usb_hcd_alloc_bandwidth(udev: dev, NULL, old_alt: alt, new_alt: iface->cur_altsetting);
1606	usb_enable_lpm(udev: dev);
1607	mutex_unlock(lock: hcd->bandwidth_mutex);
1608	return ret;
1609	}
1610	mutex_unlock(lock: hcd->bandwidth_mutex);
1611
1612	/* FIXME drivers shouldn't need to replicate/bugfix the logic here
1613	* when they implement async or easily-killable versions of this or
1614	* other "should-be-internal" functions (like clear_halt).
1615	* should hcd+usbcore postprocess control requests?
1616	*/
1617
1618	/* prevent submissions using previous endpoint settings */
1619	if (iface->cur_altsetting != alt) {
1620	remove_intf_ep_devs(intf: iface);
1621	usb_remove_sysfs_intf_files(intf: iface);
1622	}
1623	usb_disable_interface(dev, intf: iface, reset_hardware: true);
1624
1625	iface->cur_altsetting = alt;
1626
1627	/* Now that the interface is installed, re-enable LPM. */
1628	usb_unlocked_enable_lpm(udev: dev);
1629
1630	/* If the interface only has one altsetting and the device didn't
1631	* accept the request, we attempt to carry out the equivalent action
1632	* by manually clearing the HALT feature for each endpoint in the
1633	* new altsetting.
1634	*/
1635	if (manual) {
1636	for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1637	epaddr = alt->endpoint[i].desc.bEndpointAddress;
1638	pipe = __create_pipe(dev,
1639	USB_ENDPOINT_NUMBER_MASK & epaddr) |
1640	(usb_endpoint_out(epaddr) ?
1641	USB_DIR_OUT : USB_DIR_IN);
1642
1643	usb_clear_halt(dev, pipe);
1644	}
1645	}
1646
1647	/* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1648	*
1649	* Note:
1650	* Despite EP0 is always present in all interfaces/AS, the list of
1651	* endpoints from the descriptor does not contain EP0. Due to its
1652	* omnipresence one might expect EP0 being considered "affected" by
1653	* any SetInterface request and hence assume toggles need to be reset.
1654	* However, EP0 toggles are re-synced for every individual transfer
1655	* during the SETUP stage - hence EP0 toggles are "don't care" here.
1656	* (Likewise, EP0 never "halts" on well designed devices.)
1657	*/
1658	usb_enable_interface(dev, intf: iface, reset_eps: true);
1659	if (device_is_registered(dev: &iface->dev)) {
1660	usb_create_sysfs_intf_files(intf: iface);
1661	create_intf_ep_devs(intf: iface);
1662	}
1663	return 0;
1664	}
1665	EXPORT_SYMBOL_GPL(usb_set_interface);
1666
1667	/**
1668	* usb_reset_configuration - lightweight device reset
1669	* @dev: the device whose configuration is being reset
1670	*
1671	* This issues a standard SET_CONFIGURATION request to the device using
1672	* the current configuration. The effect is to reset most USB-related
1673	* state in the device, including interface altsettings (reset to zero),
1674	* endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1675	* endpoints). Other usbcore state is unchanged, including bindings of
1676	* usb device drivers to interfaces.
1677	*
1678	* Because this affects multiple interfaces, avoid using this with composite
1679	* (multi-interface) devices. Instead, the driver for each interface may
1680	* use usb_set_interface() on the interfaces it claims. Be careful though;
1681	* some devices don't support the SET_INTERFACE request, and others won't
1682	* reset all the interface state (notably endpoint state). Resetting the whole
1683	* configuration would affect other drivers' interfaces.
1684	*
1685	* The caller must own the device lock.
1686	*
1687	* Return: Zero on success, else a negative error code.
1688	*
1689	* If this routine fails the device will probably be in an unusable state
1690	* with endpoints disabled, and interfaces only partially enabled.
1691	*/
1692	int usb_reset_configuration(struct usb_device *dev)
1693	{
1694	int i, retval;
1695	struct usb_host_config *config;
1696	struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
1697
1698	if (dev->state == USB_STATE_SUSPENDED)
1699	return -EHOSTUNREACH;
1700
1701	/* caller must have locked the device and must own
1702	* the usb bus readlock (so driver bindings are stable);
1703	* calls during probe() are fine
1704	*/
1705
1706	usb_disable_device_endpoints(dev, skip_ep0: 1); /* skip ep0*/
1707
1708	config = dev->actconfig;
1709	retval = 0;
1710	mutex_lock(hcd->bandwidth_mutex);
1711	/* Disable LPM, and re-enable it once the configuration is reset, so
1712	* that the xHCI driver can recalculate the U1/U2 timeouts.
1713	*/
1714	if (usb_disable_lpm(udev: dev)) {
1715	dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1716	mutex_unlock(lock: hcd->bandwidth_mutex);
1717	return -ENOMEM;
1718	}
1719
1720	/* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1721	retval = usb_hcd_alloc_bandwidth(udev: dev, new_config: config, NULL, NULL);
1722	if (retval < 0) {
1723	usb_enable_lpm(udev: dev);
1724	mutex_unlock(lock: hcd->bandwidth_mutex);
1725	return retval;
1726	}
1727	retval = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
1728	config->desc.bConfigurationValue, 0,
1729	NULL, 0, USB_CTRL_SET_TIMEOUT,
1730	GFP_NOIO);
1731	if (retval) {
1732	usb_hcd_alloc_bandwidth(udev: dev, NULL, NULL, NULL);
1733	usb_enable_lpm(udev: dev);
1734	mutex_unlock(lock: hcd->bandwidth_mutex);
1735	return retval;
1736	}
1737	mutex_unlock(lock: hcd->bandwidth_mutex);
1738
1739	/* re-init hc/hcd interface/endpoint state */
1740	for (i = 0; i < config->desc.bNumInterfaces; i++) {
1741	struct usb_interface *intf = config->interface[i];
1742	struct usb_host_interface *alt;
1743
1744	alt = usb_altnum_to_altsetting(intf, altnum: 0);
1745
1746	/* No altsetting 0? We'll assume the first altsetting.
1747	* We could use a GetInterface call, but if a device is
1748	* so non-compliant that it doesn't have altsetting 0
1749	* then I wouldn't trust its reply anyway.
1750	*/
1751	if (!alt)
1752	alt = &intf->altsetting[0];
1753
1754	if (alt != intf->cur_altsetting) {
1755	remove_intf_ep_devs(intf);
1756	usb_remove_sysfs_intf_files(intf);
1757	}
1758	intf->cur_altsetting = alt;
1759	usb_enable_interface(dev, intf, reset_eps: true);
1760	if (device_is_registered(dev: &intf->dev)) {
1761	usb_create_sysfs_intf_files(intf);
1762	create_intf_ep_devs(intf);
1763	}
1764	}
1765	/* Now that the interfaces are installed, re-enable LPM. */
1766	usb_unlocked_enable_lpm(udev: dev);
1767	return 0;
1768	}
1769	EXPORT_SYMBOL_GPL(usb_reset_configuration);
1770
1771	static void usb_release_interface(struct device *dev)
1772	{
1773	struct usb_interface *intf = to_usb_interface(dev);
1774	struct usb_interface_cache *intfc =
1775	altsetting_to_usb_interface_cache(intf->altsetting);
1776
1777	kref_put(kref: &intfc->ref, release: usb_release_interface_cache);
1778	usb_put_dev(interface_to_usbdev(intf));
1779	of_node_put(node: dev->of_node);
1780	kfree(objp: intf);
1781	}
1782
1783	/*
1784	* usb_deauthorize_interface - deauthorize an USB interface
1785	*
1786	* @intf: USB interface structure
1787	*/
1788	void usb_deauthorize_interface(struct usb_interface *intf)
1789	{
1790	struct device *dev = &intf->dev;
1791
1792	device_lock(dev: dev->parent);
1793
1794	if (intf->authorized) {
1795	device_lock(dev);
1796	intf->authorized = 0;
1797	device_unlock(dev);
1798
1799	usb_forced_unbind_intf(intf);
1800	}
1801
1802	device_unlock(dev: dev->parent);
1803	}
1804
1805	/*
1806	* usb_authorize_interface - authorize an USB interface
1807	*
1808	* @intf: USB interface structure
1809	*/
1810	void usb_authorize_interface(struct usb_interface *intf)
1811	{
1812	struct device *dev = &intf->dev;
1813
1814	if (!intf->authorized) {
1815	device_lock(dev);
1816	intf->authorized = 1; /* authorize interface */
1817	device_unlock(dev);
1818	}
1819	}
1820
1821	static int usb_if_uevent(const struct device *dev, struct kobj_uevent_env *env)
1822	{
1823	const struct usb_device *usb_dev;
1824	const struct usb_interface *intf;
1825	const struct usb_host_interface *alt;
1826
1827	intf = to_usb_interface(dev);
1828	usb_dev = interface_to_usbdev(intf);
1829	alt = intf->cur_altsetting;
1830
1831	if (add_uevent_var(env, format: "INTERFACE=%d/%d/%d",
1832	alt->desc.bInterfaceClass,
1833	alt->desc.bInterfaceSubClass,
1834	alt->desc.bInterfaceProtocol))
1835	return -ENOMEM;
1836
1837	if (add_uevent_var(env,
1838	format: "MODALIAS=usb:"
1839	"v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1840	le16_to_cpu(usb_dev->descriptor.idVendor),
1841	le16_to_cpu(usb_dev->descriptor.idProduct),
1842	le16_to_cpu(usb_dev->descriptor.bcdDevice),
1843	usb_dev->descriptor.bDeviceClass,
1844	usb_dev->descriptor.bDeviceSubClass,
1845	usb_dev->descriptor.bDeviceProtocol,
1846	alt->desc.bInterfaceClass,
1847	alt->desc.bInterfaceSubClass,
1848	alt->desc.bInterfaceProtocol,
1849	alt->desc.bInterfaceNumber))
1850	return -ENOMEM;
1851
1852	return 0;
1853	}
1854
1855	const struct device_type usb_if_device_type = {
1856	.name = "usb_interface",
1857	.release = usb_release_interface,
1858	.uevent = usb_if_uevent,
1859	};
1860
1861	static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1862	struct usb_host_config *config,
1863	u8 inum)
1864	{
1865	struct usb_interface_assoc_descriptor *retval = NULL;
1866	struct usb_interface_assoc_descriptor *intf_assoc;
1867	int first_intf;
1868	int last_intf;
1869	int i;
1870
1871	for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1872	intf_assoc = config->intf_assoc[i];
1873	if (intf_assoc->bInterfaceCount == 0)
1874	continue;
1875
1876	first_intf = intf_assoc->bFirstInterface;
1877	last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1878	if (inum >= first_intf && inum <= last_intf) {
1879	if (!retval)
1880	retval = intf_assoc;
1881	else
1882	dev_err(&dev->dev, "Interface #%d referenced"
1883	" by multiple IADs\n", inum);
1884	}
1885	}
1886
1887	return retval;
1888	}
1889
1890
1891	/*
1892	* Internal function to queue a device reset
1893	* See usb_queue_reset_device() for more details
1894	*/
1895	static void __usb_queue_reset_device(struct work_struct *ws)
1896	{
1897	int rc;
1898	struct usb_interface *iface =
1899	container_of(ws, struct usb_interface, reset_ws);
1900	struct usb_device *udev = interface_to_usbdev(iface);
1901
1902	rc = usb_lock_device_for_reset(udev, iface);
1903	if (rc >= 0) {
1904	usb_reset_device(dev: udev);
1905	usb_unlock_device(udev);
1906	}
1907	usb_put_intf(intf: iface); /* Undo _get_ in usb_queue_reset_device() */
1908	}
1909
1910	/*
1911	* Internal function to set the wireless_status sysfs attribute
1912	* See usb_set_wireless_status() for more details
1913	*/
1914	static void __usb_wireless_status_intf(struct work_struct *ws)
1915	{
1916	struct usb_interface *iface =
1917	container_of(ws, struct usb_interface, wireless_status_work);
1918
1919	device_lock(dev: iface->dev.parent);
1920	if (iface->sysfs_files_created)
1921	usb_update_wireless_status_attr(intf: iface);
1922	device_unlock(dev: iface->dev.parent);
1923	usb_put_intf(intf: iface); /* Undo _get_ in usb_set_wireless_status() */
1924	}
1925
1926	/**
1927	* usb_set_wireless_status - sets the wireless_status struct member
1928	* @iface: the interface to modify
1929	* @status: the new wireless status
1930	*
1931	* Set the wireless_status struct member to the new value, and emit
1932	* sysfs changes as necessary.
1933	*
1934	* Returns: 0 on success, -EALREADY if already set.
1935	*/
1936	int usb_set_wireless_status(struct usb_interface *iface,
1937	enum usb_wireless_status status)
1938	{
1939	if (iface->wireless_status == status)
1940	return -EALREADY;
1941
1942	usb_get_intf(intf: iface);
1943	iface->wireless_status = status;
1944	schedule_work(work: &iface->wireless_status_work);
1945
1946	return 0;
1947	}
1948	EXPORT_SYMBOL_GPL(usb_set_wireless_status);
1949
1950	/*
1951	* usb_set_configuration - Makes a particular device setting be current
1952	* @dev: the device whose configuration is being updated
1953	* @configuration: the configuration being chosen.
1954	*
1955	* Context: task context, might sleep. Caller holds device lock.
1956	*
1957	* This is used to enable non-default device modes. Not all devices
1958	* use this kind of configurability; many devices only have one
1959	* configuration.
1960	*
1961	* @configuration is the value of the configuration to be installed.
1962	* According to the USB spec (e.g. section 9.1.1.5), configuration values
1963	* must be non-zero; a value of zero indicates that the device in
1964	* unconfigured. However some devices erroneously use 0 as one of their
1965	* configuration values. To help manage such devices, this routine will
1966	* accept @configuration = -1 as indicating the device should be put in
1967	* an unconfigured state.
1968	*
1969	* USB device configurations may affect Linux interoperability,
1970	* power consumption and the functionality available. For example,
1971	* the default configuration is limited to using 100mA of bus power,
1972	* so that when certain device functionality requires more power,
1973	* and the device is bus powered, that functionality should be in some
1974	* non-default device configuration. Other device modes may also be
1975	* reflected as configuration options, such as whether two ISDN
1976	* channels are available independently; and choosing between open
1977	* standard device protocols (like CDC) or proprietary ones.
1978	*
1979	* Note that a non-authorized device (dev->authorized == 0) will only
1980	* be put in unconfigured mode.
1981	*
1982	* Note that USB has an additional level of device configurability,
1983	* associated with interfaces. That configurability is accessed using
1984	* usb_set_interface().
1985	*
1986	* This call is synchronous. The calling context must be able to sleep,
1987	* must own the device lock, and must not hold the driver model's USB
1988	* bus mutex; usb interface driver probe() methods cannot use this routine.
1989	*
1990	* Returns zero on success, or else the status code returned by the
1991	* underlying call that failed. On successful completion, each interface
1992	* in the original device configuration has been destroyed, and each one
1993	* in the new configuration has been probed by all relevant usb device
1994	* drivers currently known to the kernel.
1995	*/
1996	int usb_set_configuration(struct usb_device *dev, int configuration)
1997	{
1998	int i, ret;
1999	struct usb_host_config *cp = NULL;
2000	struct usb_interface **new_interfaces = NULL;
2001	struct usb_hcd *hcd = bus_to_hcd(bus: dev->bus);
2002	int n, nintf;
2003
2004	if (dev->authorized == 0 || configuration == -1)
2005	configuration = 0;
2006	else {
2007	for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
2008	if (dev->config[i].desc.bConfigurationValue ==
2009	configuration) {
2010	cp = &dev->config[i];
2011	break;
2012	}
2013	}
2014	}
2015	if ((!cp && configuration != 0))
2016	return -EINVAL;
2017
2018	/* The USB spec says configuration 0 means unconfigured.
2019	* But if a device includes a configuration numbered 0,
2020	* we will accept it as a correctly configured state.
2021	* Use -1 if you really want to unconfigure the device.
2022	*/
2023	if (cp && configuration == 0)
2024	dev_warn(&dev->dev, "config 0 descriptor??\n");
2025
2026	/* Allocate memory for new interfaces before doing anything else,
2027	* so that if we run out then nothing will have changed. */
2028	n = nintf = 0;
2029	if (cp) {
2030	nintf = cp->desc.bNumInterfaces;
2031	new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
2032	GFP_NOIO);
2033	if (!new_interfaces)
2034	return -ENOMEM;
2035
2036	for (; n < nintf; ++n) {
2037	new_interfaces[n] = kzalloc(
2038	sizeof(struct usb_interface),
2039	GFP_NOIO);
2040	if (!new_interfaces[n]) {
2041	ret = -ENOMEM;
2042	free_interfaces:
2043	while (--n >= 0)
2044	kfree(objp: new_interfaces[n]);
2045	kfree(objp: new_interfaces);
2046	return ret;
2047	}
2048	}
2049
2050	i = dev->bus_mA - usb_get_max_power(udev: dev, c: cp);
2051	if (i < 0)
2052	dev_warn(&dev->dev, "new config #%d exceeds power "
2053	"limit by %dmA\n",
2054	configuration, -i);
2055	}
2056
2057	/* Wake up the device so we can send it the Set-Config request */
2058	ret = usb_autoresume_device(udev: dev);
2059	if (ret)
2060	goto free_interfaces;
2061
2062	/* if it's already configured, clear out old state first.
2063	* getting rid of old interfaces means unbinding their drivers.
2064	*/
2065	if (dev->state != USB_STATE_ADDRESS)
2066	usb_disable_device(dev, skip_ep0: 1); /* Skip ep0 */
2067
2068	/* Get rid of pending async Set-Config requests for this device */
2069	cancel_async_set_config(udev: dev);
2070
2071	/* Make sure we have bandwidth (and available HCD resources) for this
2072	* configuration. Remove endpoints from the schedule if we're dropping
2073	* this configuration to set configuration 0. After this point, the
2074	* host controller will not allow submissions to dropped endpoints. If
2075	* this call fails, the device state is unchanged.
2076	*/
2077	mutex_lock(hcd->bandwidth_mutex);
2078	/* Disable LPM, and re-enable it once the new configuration is
2079	* installed, so that the xHCI driver can recalculate the U1/U2
2080	* timeouts.
2081	*/
2082	if (dev->actconfig && usb_disable_lpm(udev: dev)) {
2083	dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
2084	mutex_unlock(lock: hcd->bandwidth_mutex);
2085	ret = -ENOMEM;
2086	goto free_interfaces;
2087	}
2088	ret = usb_hcd_alloc_bandwidth(udev: dev, new_config: cp, NULL, NULL);
2089	if (ret < 0) {
2090	if (dev->actconfig)
2091	usb_enable_lpm(udev: dev);
2092	mutex_unlock(lock: hcd->bandwidth_mutex);
2093	usb_autosuspend_device(udev: dev);
2094	goto free_interfaces;
2095	}
2096
2097	/*
2098	* Initialize the new interface structures and the
2099	* hc/hcd/usbcore interface/endpoint state.
2100	*/
2101	for (i = 0; i < nintf; ++i) {
2102	struct usb_interface_cache *intfc;
2103	struct usb_interface *intf;
2104	struct usb_host_interface *alt;
2105	u8 ifnum;
2106
2107	cp->interface[i] = intf = new_interfaces[i];
2108	intfc = cp->intf_cache[i];
2109	intf->altsetting = intfc->altsetting;
2110	intf->num_altsetting = intfc->num_altsetting;
2111	intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
2112	kref_get(kref: &intfc->ref);
2113
2114	alt = usb_altnum_to_altsetting(intf, altnum: 0);
2115
2116	/* No altsetting 0? We'll assume the first altsetting.
2117	* We could use a GetInterface call, but if a device is
2118	* so non-compliant that it doesn't have altsetting 0
2119	* then I wouldn't trust its reply anyway.
2120	*/
2121	if (!alt)
2122	alt = &intf->altsetting[0];
2123
2124	ifnum = alt->desc.bInterfaceNumber;
2125	intf->intf_assoc = find_iad(dev, config: cp, inum: ifnum);
2126	intf->cur_altsetting = alt;
2127	usb_enable_interface(dev, intf, reset_eps: true);
2128	intf->dev.parent = &dev->dev;
2129	if (usb_of_has_combined_node(udev: dev)) {
2130	device_set_of_node_from_dev(dev: &intf->dev, dev2: &dev->dev);
2131	} else {
2132	intf->dev.of_node = usb_of_get_interface_node(udev: dev,
2133	config: configuration, ifnum);
2134	}
2135	ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
2136	intf->dev.driver = NULL;
2137	intf->dev.bus = &usb_bus_type;
2138	intf->dev.type = &usb_if_device_type;
2139	intf->dev.groups = usb_interface_groups;
2140	INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
2141	INIT_WORK(&intf->wireless_status_work, __usb_wireless_status_intf);
2142	intf->minor = -1;
2143	device_initialize(dev: &intf->dev);
2144	pm_runtime_no_callbacks(dev: &intf->dev);
2145	dev_set_name(dev: &intf->dev, name: "%d-%s:%d.%d", dev->bus->busnum,
2146	dev->devpath, configuration, ifnum);
2147	usb_get_dev(dev);
2148	}
2149	kfree(objp: new_interfaces);
2150
2151	ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
2152	configuration, 0, NULL, 0,
2153	USB_CTRL_SET_TIMEOUT, GFP_NOIO);
2154	if (ret && cp) {
2155	/*
2156	* All the old state is gone, so what else can we do?
2157	* The device is probably useless now anyway.
2158	*/
2159	usb_hcd_alloc_bandwidth(udev: dev, NULL, NULL, NULL);
2160	for (i = 0; i < nintf; ++i) {
2161	usb_disable_interface(dev, intf: cp->interface[i], reset_hardware: true);
2162	put_device(dev: &cp->interface[i]->dev);
2163	cp->interface[i] = NULL;
2164	}
2165	cp = NULL;
2166	}
2167
2168	dev->actconfig = cp;
2169	mutex_unlock(lock: hcd->bandwidth_mutex);
2170
2171	if (!cp) {
2172	usb_set_device_state(udev: dev, new_state: USB_STATE_ADDRESS);
2173
2174	/* Leave LPM disabled while the device is unconfigured. */
2175	usb_autosuspend_device(udev: dev);
2176	return ret;
2177	}
2178	usb_set_device_state(udev: dev, new_state: USB_STATE_CONFIGURED);
2179
2180	if (cp->string == NULL &&
2181	!(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2182	cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2183
2184	/* Now that the interfaces are installed, re-enable LPM. */
2185	usb_unlocked_enable_lpm(udev: dev);
2186	/* Enable LTM if it was turned off by usb_disable_device. */
2187	usb_enable_ltm(udev: dev);
2188
2189	/* Now that all the interfaces are set up, register them
2190	* to trigger binding of drivers to interfaces. probe()
2191	* routines may install different altsettings and may
2192	* claim() any interfaces not yet bound. Many class drivers
2193	* need that: CDC, audio, video, etc.
2194	*/
2195	for (i = 0; i < nintf; ++i) {
2196	struct usb_interface *intf = cp->interface[i];
2197
2198	if (intf->dev.of_node &&
2199	!of_device_is_available(device: intf->dev.of_node)) {
2200	dev_info(&dev->dev, "skipping disabled interface %d\n",
2201	intf->cur_altsetting->desc.bInterfaceNumber);
2202	continue;
2203	}
2204
2205	dev_dbg(&dev->dev,
2206	"adding %s (config #%d, interface %d)\n",
2207	dev_name(&intf->dev), configuration,
2208	intf->cur_altsetting->desc.bInterfaceNumber);
2209	device_enable_async_suspend(dev: &intf->dev);
2210	ret = device_add(dev: &intf->dev);
2211	if (ret != 0) {
2212	dev_err(&dev->dev, "device_add(%s) --> %d\n",
2213	dev_name(&intf->dev), ret);
2214	continue;
2215	}
2216	create_intf_ep_devs(intf);
2217	}
2218
2219	usb_autosuspend_device(udev: dev);
2220	return 0;
2221	}
2222	EXPORT_SYMBOL_GPL(usb_set_configuration);
2223
2224	static LIST_HEAD(set_config_list);
2225	static DEFINE_SPINLOCK(set_config_lock);
2226
2227	struct set_config_request {
2228	struct usb_device *udev;
2229	int config;
2230	struct work_struct work;
2231	struct list_head node;
2232	};
2233
2234	/* Worker routine for usb_driver_set_configuration() */
2235	static void driver_set_config_work(struct work_struct *work)
2236	{
2237	struct set_config_request *req =
2238	container_of(work, struct set_config_request, work);
2239	struct usb_device *udev = req->udev;
2240
2241	usb_lock_device(udev);
2242	spin_lock(lock: &set_config_lock);
2243	list_del(entry: &req->node);
2244	spin_unlock(lock: &set_config_lock);
2245
2246	if (req->config >= -1) /* Is req still valid? */
2247	usb_set_configuration(udev, req->config);
2248	usb_unlock_device(udev);
2249	usb_put_dev(dev: udev);
2250	kfree(objp: req);
2251	}
2252
2253	/* Cancel pending Set-Config requests for a device whose configuration
2254	* was just changed
2255	*/
2256	static void cancel_async_set_config(struct usb_device *udev)
2257	{
2258	struct set_config_request *req;
2259
2260	spin_lock(lock: &set_config_lock);
2261	list_for_each_entry(req, &set_config_list, node) {
2262	if (req->udev == udev)
2263	req->config = -999; /* Mark as cancelled */
2264	}
2265	spin_unlock(lock: &set_config_lock);
2266	}
2267
2268	/**
2269	* usb_driver_set_configuration - Provide a way for drivers to change device configurations
2270	* @udev: the device whose configuration is being updated
2271	* @config: the configuration being chosen.
2272	* Context: In process context, must be able to sleep
2273	*
2274	* Device interface drivers are not allowed to change device configurations.
2275	* This is because changing configurations will destroy the interface the
2276	* driver is bound to and create new ones; it would be like a floppy-disk
2277	* driver telling the computer to replace the floppy-disk drive with a
2278	* tape drive!
2279	*
2280	* Still, in certain specialized circumstances the need may arise. This
2281	* routine gets around the normal restrictions by using a work thread to
2282	* submit the change-config request.
2283	*
2284	* Return: 0 if the request was successfully queued, error code otherwise.
2285	* The caller has no way to know whether the queued request will eventually
2286	* succeed.
2287	*/
2288	int usb_driver_set_configuration(struct usb_device *udev, int config)
2289	{
2290	struct set_config_request *req;
2291
2292	req = kmalloc(sizeof(*req), GFP_KERNEL);
2293	if (!req)
2294	return -ENOMEM;
2295	req->udev = udev;
2296	req->config = config;
2297	INIT_WORK(&req->work, driver_set_config_work);
2298
2299	spin_lock(lock: &set_config_lock);
2300	list_add(new: &req->node, head: &set_config_list);
2301	spin_unlock(lock: &set_config_lock);
2302
2303	usb_get_dev(dev: udev);
2304	schedule_work(work: &req->work);
2305	return 0;
2306	}
2307	EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2308
2309	/**
2310	* cdc_parse_cdc_header - parse the extra headers present in CDC devices
2311	* @hdr: the place to put the results of the parsing
2312	* @intf: the interface for which parsing is requested
2313	* @buffer: pointer to the extra headers to be parsed
2314	* @buflen: length of the extra headers
2315	*
2316	* This evaluates the extra headers present in CDC devices which
2317	* bind the interfaces for data and control and provide details
2318	* about the capabilities of the device.
2319	*
2320	* Return: number of descriptors parsed or -EINVAL
2321	* if the header is contradictory beyond salvage
2322	*/
2323
2324	int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2325	struct usb_interface *intf,
2326	u8 *buffer,
2327	int buflen)
2328	{
2329	/* duplicates are ignored */
2330	struct usb_cdc_union_desc *union_header = NULL;
2331
2332	/* duplicates are not tolerated */
2333	struct usb_cdc_header_desc *header = NULL;
2334	struct usb_cdc_ether_desc *ether = NULL;
2335	struct usb_cdc_mdlm_detail_desc *detail = NULL;
2336	struct usb_cdc_mdlm_desc *desc = NULL;
2337
2338	unsigned int elength;
2339	int cnt = 0;
2340
2341	memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2342	hdr->phonet_magic_present = false;
2343	while (buflen > 0) {
2344	elength = buffer[0];
2345	if (!elength) {
2346	dev_err(&intf->dev, "skipping garbage byte\n");
2347	elength = 1;
2348	goto next_desc;
2349	}
2350	if ((buflen < elength) || (elength < 3)) {
2351	dev_err(&intf->dev, "invalid descriptor buffer length\n");
2352	break;
2353	}
2354	if (buffer[1] != USB_DT_CS_INTERFACE) {
2355	dev_err(&intf->dev, "skipping garbage\n");
2356	goto next_desc;
2357	}
2358
2359	switch (buffer[2]) {
2360	case USB_CDC_UNION_TYPE: /* we've found it */
2361	if (elength < sizeof(struct usb_cdc_union_desc))
2362	goto next_desc;
2363	if (union_header) {
2364	dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2365	goto next_desc;
2366	}
2367	union_header = (struct usb_cdc_union_desc *)buffer;
2368	break;
2369	case USB_CDC_COUNTRY_TYPE:
2370	if (elength < sizeof(struct usb_cdc_country_functional_desc))
2371	goto next_desc;
2372	hdr->usb_cdc_country_functional_desc =
2373	(struct usb_cdc_country_functional_desc *)buffer;
2374	break;
2375	case USB_CDC_HEADER_TYPE:
2376	if (elength != sizeof(struct usb_cdc_header_desc))
2377	goto next_desc;
2378	if (header)
2379	return -EINVAL;
2380	header = (struct usb_cdc_header_desc *)buffer;
2381	break;
2382	case USB_CDC_ACM_TYPE:
2383	if (elength < sizeof(struct usb_cdc_acm_descriptor))
2384	goto next_desc;
2385	hdr->usb_cdc_acm_descriptor =
2386	(struct usb_cdc_acm_descriptor *)buffer;
2387	break;
2388	case USB_CDC_ETHERNET_TYPE:
2389	if (elength != sizeof(struct usb_cdc_ether_desc))
2390	goto next_desc;
2391	if (ether)
2392	return -EINVAL;
2393	ether = (struct usb_cdc_ether_desc *)buffer;
2394	break;
2395	case USB_CDC_CALL_MANAGEMENT_TYPE:
2396	if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2397	goto next_desc;
2398	hdr->usb_cdc_call_mgmt_descriptor =
2399	(struct usb_cdc_call_mgmt_descriptor *)buffer;
2400	break;
2401	case USB_CDC_DMM_TYPE:
2402	if (elength < sizeof(struct usb_cdc_dmm_desc))
2403	goto next_desc;
2404	hdr->usb_cdc_dmm_desc =
2405	(struct usb_cdc_dmm_desc *)buffer;
2406	break;
2407	case USB_CDC_MDLM_TYPE:
2408	if (elength < sizeof(struct usb_cdc_mdlm_desc))
2409	goto next_desc;
2410	if (desc)
2411	return -EINVAL;
2412	desc = (struct usb_cdc_mdlm_desc *)buffer;
2413	break;
2414	case USB_CDC_MDLM_DETAIL_TYPE:
2415	if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2416	goto next_desc;
2417	if (detail)
2418	return -EINVAL;
2419	detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2420	break;
2421	case USB_CDC_NCM_TYPE:
2422	if (elength < sizeof(struct usb_cdc_ncm_desc))
2423	goto next_desc;
2424	hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2425	break;
2426	case USB_CDC_MBIM_TYPE:
2427	if (elength < sizeof(struct usb_cdc_mbim_desc))
2428	goto next_desc;
2429
2430	hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2431	break;
2432	case USB_CDC_MBIM_EXTENDED_TYPE:
2433	if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2434	goto next_desc;
2435	hdr->usb_cdc_mbim_extended_desc =
2436	(struct usb_cdc_mbim_extended_desc *)buffer;
2437	break;
2438	case CDC_PHONET_MAGIC_NUMBER:
2439	hdr->phonet_magic_present = true;
2440	break;
2441	default:
2442	/*
2443	* there are LOTS more CDC descriptors that
2444	* could legitimately be found here.
2445	*/
2446	dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2447	buffer[2], elength);
2448	goto next_desc;
2449	}
2450	cnt++;
2451	next_desc:
2452	buflen -= elength;
2453	buffer += elength;
2454	}
2455	hdr->usb_cdc_union_desc = union_header;
2456	hdr->usb_cdc_header_desc = header;
2457	hdr->usb_cdc_mdlm_detail_desc = detail;
2458	hdr->usb_cdc_mdlm_desc = desc;
2459	hdr->usb_cdc_ether_desc = ether;
2460	return cnt;
2461	}
2462
2463	EXPORT_SYMBOL(cdc_parse_cdc_header);
2464