[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 <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 149aa8bfb1fe4e2bb353ae49f490e7dc081ea48a..dec1337c4775d0048fe56a3d1befc5bc718252c3 100644 (file)
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -608,12 +608,12 @@ int usb_get_descriptor(struct usb_device *dev, unsigned char type, unsigned char
        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;