[3.13.y.z extended stable] Patch "xhci: Use correct SLOT ID when handling a reset device command" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    xhci: Use correct SLOT ID when handling a reset device command

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From bb7cb247d8067e5b1a7cd266301b89276aca01d2 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman at linux.intel.com>
Date: Tue, 24 Jun 2014 17:14:40 +0300
Subject: xhci: Use correct SLOT ID when handling a reset device command

commit 6fcfb0d682a8212d321a6131adc94daf0905992a upstream.

Command completion events normally include command completion status,
SLOT_ID, and a pointer to the original command. Reset device command
completion SLOT_ID may be zero according to xhci specs 4.6.11.

VIA controllers set the SLOT_ID to zero, triggering a WARN_ON in the
command completion handler.

Use the SLOT ID found from the original command instead.

This patch should be applied to stable kernels since 3.13 that contain
the commit 20e7acb13ff48fbc884d5918c3697c27de63922a
"xhci: use completion event's slot id rather than dig it out of command"

Reported-by: Saran Neti <sarannmr at gmail.com>
Tested-by: Saran Neti <sarannmr at gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/host/xhci-ring.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 82b5967..da3a91b 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1592,8 +1592,11 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
 		xhci_handle_cmd_reset_ep(xhci, slot_id, cmd_trb, cmd_comp_code);
 		break;
 	case TRB_RESET_DEV:
-		WARN_ON(slot_id != TRB_TO_SLOT_ID(
-				le32_to_cpu(cmd_trb->generic.field[3])));
+		/* SLOT_ID field in reset device cmd completion event TRB is 0.
+		 * Use the SLOT_ID from the command TRB instead (xhci 4.6.11)
+		 */
+		slot_id = TRB_TO_SLOT_ID(
+				le32_to_cpu(cmd_trb->generic.field[3]));
 		xhci_handle_cmd_reset_dev(xhci, slot_id, event);
 		break;
 	case TRB_NEC_GET_FW:
--
1.9.1