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>
CC: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2007-08-20 10:45:28 -04:00 committed by Greg Kroah-Hartman
parent 3b79cc2670
commit c39772d82a

View file

@ -637,12 +637,12 @@ 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;