From: Alan Stern <stern@rowland.harvard.edu>
Date: Mon, 20 Aug 2007 14:45:28 +0000 (-0400)
Subject: USB: allow retry on descriptor fetch errors
X-Git-Tag: v2.6.23-rc4~29^2~9
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c39772d82ad453647ea4bf9d793010d86ef5e597;p=linux-2.6

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>
---

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index b6bd05e3d4..5498506e9c 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -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;