Split "create" and "setup" parts for uinput devices creation

ndreys · ndreys · commit 34fe42c0b5bf · 2018-08-09T16:04:07.000-07:00
In order to be able to enable EV_FF in uinput device, ff_max_effects
fields needs to be set to a non-zero value. However the ordering of
execution in uinput.py does not allow for that because indvidual
events are enabled before _uinput.create() is invoked.

In order to accomodate EV_FF, split _uinput.create() into two
functions:
    - _uinput.setup(), which does the majority of device
    configuration.

    - _uinput.create(), which only creates the device without
      changing any of its configuration

On top of that, change the code in uinput.py to make the call to
setup() before individual events are enabled to enable adding
ff_max_effects configuration in follow-up commits.
diff --git a/evdev/uinput.c b/evdev/uinput.c
@@ -69,7 +69,7 @@ uinput_set_phys(PyObject *self, PyObject *args)
 
 
 static PyObject *
-uinput_create(PyObject *self, PyObject *args) {
+uinput_setup(PyObject *self, PyObject *args) {
     int fd, len, i, abscode;
     uint16_t vendor, product, version, bustype;
 
@@ -113,6 +113,22 @@ uinput_create(PyObject *self, PyObject *args) {
     /*         goto on_err; */
     /* } */
 
+    Py_RETURN_NONE;
+
+    on_err:
+        _uinput_close(fd);
+        PyErr_SetFromErrno(PyExc_IOError);
+        return NULL;
+}
+
+static PyObject *
+uinput_create(PyObject *self, PyObject *args)
+{
+    int fd;
+
+    int ret = PyArg_ParseTuple(args, "i", &fd);
+    if (!ret) return NULL;
+
     if (ioctl(fd, UI_DEV_CREATE) < 0)
         goto on_err;
 
@@ -214,6 +230,9 @@ static PyMethodDef MethodTable[] = {
     { "open",  uinput_open, METH_VARARGS,
       "Open uinput device node."},
 
+    { "setup",  uinput_setup, METH_VARARGS,
+      "Set an uinput device up."},
+
     { "create",  uinput_create, METH_VARARGS,
       "Create an uinput device."},
 
diff --git a/evdev/uinput.py b/evdev/uinput.py
@@ -131,6 +131,8 @@ def __init__(self,
         # Set phys name
         _uinput.set_phys(self.fd, phys)
 
+        _uinput.setup(self.fd, name, vendor, product, version, bustype, absinfo)
+
         # Set device capabilities.
         for etype, codes in events.items():
             for code in codes:
@@ -149,7 +151,7 @@ def __init__(self,
                 _uinput.enable(self.fd, etype, code)
 
         # Create the uinput device.
-        _uinput.create(self.fd, name, vendor, product, version, bustype, absinfo)
+        _uinput.create(self.fd)
 
         #: An :class:`InputDevice <evdev.device.InputDevice>` instance
         #: for the fake input device. ``None`` if the device cannot be
