Patch "usb: retry reset if a device times out" has been added to the 4.4-stable tree

Patch "usb: retry reset if a device times out" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    usb: retry reset if a device times out

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-retry-reset-if-a-device-times-out.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 264904ccc33c604d4b3141bbd33808152dfac45b Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Wed, 10 Feb 2016 11:33:18 +0100
Subject: usb: retry reset if a device times out

From: Oliver Neukum <oneukum@suse.com>

commit 264904ccc33c604d4b3141bbd33808152dfac45b upstream.

Some devices I got show an inability to operate right after
power on if they are already connected. They are beyond recovery
if the descriptors are requested multiple times. So in case of
a timeout we rather bail early and reset again. But it must be
done only on the first loop lest we get into a reset/time out
spiral that can be overcome with a retry.

This patch is a rework of a patch that fell through the cracks.
http://www.spinics.net/lists/linux-usb/msg103263.html

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/core/hub.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4426,7 +4426,13 @@ hub_port_init(struct usb_hub *hub, struc
 						r = -EPROTO;
 					break;
 				}
-				if (r == 0)
+				/*
+				 * Some devices time out if they are powered on
+				 * when already connected. They need a second
+				 * reset. But only on the first attempt,
+				 * lest we get into a time out/reset loop
+				 */
+				if (r == 0  || (r == -ETIMEDOUT && j == 0))
 					break;
 			}
 			udev->descriptor.bMaxPacketSize0 =


Patches currently in stable-queue which might be from oneukum@suse.com are

queue-4.4/usb-cdc-acm-more-sanity-checking.patch
queue-4.4/usb-mct_u232-add-sanity-checking-in-probe.patch
queue-4.4/usb-digi_acceleport-do-sanity-checking-for-the-number-of-ports.patch
queue-4.4/usb-cypress_m8-add-endpoint-sanity-check.patch
queue-4.4/usb-retry-reset-if-a-device-times-out.patch
queue-4.4/usb-hub-fix-a-typo-in-hub_port_init-leading-to-wrong-logic.patch
queue-4.4/usb-usb_driver_claim_interface-add-sanity-checking.patch