stmhal: Add retry to SD card init.

dpgeorge · dpgeorge · commit 072bd07f1789 · 2014-10-20T00:04:27.000+01:00
This fixed an issue with a certain SD card sometimes not initialising first time round. See issue adafruit#822 for related, and thanks to @iabdalkader for the idea.
diff --git a/stmhal/sdcard.c b/stmhal/sdcard.c
@@ -105,10 +105,13 @@ bool sdcard_power_on(void) {
     sd_handle.Init.HardwareFlowControl = SDIO_HARDWARE_FLOW_CONTROL_DISABLE;
     sd_handle.Init.ClockDiv            = SDIO_TRANSFER_CLK_DIV;
 
-    // init the SD interface
+    // init the SD interface, with retry if it's not ready yet
     HAL_SD_CardInfoTypedef cardinfo;
-    if (HAL_SD_Init(&sd_handle, &cardinfo) != SD_OK) {
-        goto error;
+    for (int retry = 10; HAL_SD_Init(&sd_handle, &cardinfo) != SD_OK; retry--) {
+        if (retry == 0) {
+            goto error;
+        }
+        HAL_Delay(50);
     }
 
     // configure the SD bus width for wide operation
