[PATCH] USB: allow retry on descriptor fetch errors

This patch (as964) was suggested by Steffen Koepf.  It makes
usb_get_descriptor() retry on all errors other than ETIMEDOUT, instead
of only on EPIPE.  This helps with some devices.

Signed-off-by: Alan Stern <[email protected]>

---

Index: usb-2.6/drivers/usb/core/message.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/message.c
+++ usb-2.6/drivers/usb/core/message.c
@@ -639,12 +639,12 @@ int usb_get_descriptor(struct usb_device
 	memset(buf,0,size);	// Make sure we parse really received data
 
 	for (i = 0; i < 3; ++i) {
-		/* retry on length 0 or stall; some devices are flakey */
+		/* retry on length 0 or error; some devices are flakey */
 		result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 				USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 				(type << 8) + index, 0, buf, size,
 				USB_CTRL_GET_TIMEOUT);
-		if (result == 0 || result == -EPIPE)
+		if (result <= 0 && result != -ETIMEDOUT)
 			continue;
 		if (result > 1 && ((u8 *)buf)[1] != type) {
 			result = -EPROTO;


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