From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5AB6C433F5 for ; Fri, 3 Dec 2021 15:33:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381808AbhLCPgz (ORCPT ); Fri, 3 Dec 2021 10:36:55 -0500 Received: from mxout1-ec2-va.apache.org ([3.227.148.255]:54624 "EHLO mxout1-ec2-va.apache.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381772AbhLCPgu (ORCPT ); Fri, 3 Dec 2021 10:36:50 -0500 Received: from mail.apache.org (mailroute1-lw-us.apache.org [207.244.88.153]) by mxout1-ec2-va.apache.org (ASF Mail Server at mxout1-ec2-va.apache.org) with SMTP id 4488C3F2FB for ; Fri, 3 Dec 2021 15:33:25 +0000 (UTC) Received: (qmail 95748 invoked by uid 99); 3 Dec 2021 15:33:25 -0000 Received: from ec2-52-204-25-47.compute-1.amazonaws.com (HELO mailrelay1-ec2-va.apache.org) (52.204.25.47) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 03 Dec 2021 15:33:25 +0000 Received: from [10.23.2.106] (unknown [51.154.28.112]) by mailrelay1-ec2-va.apache.org (ASF Mail Server at mailrelay1-ec2-va.apache.org) with ESMTPSA id 4B3E23E977; Fri, 3 Dec 2021 15:33:24 +0000 (UTC) Message-ID: Subject: Re: Regression: plugging in USB scanner breaks all USB functionality From: Robert Munteanu To: Greg Kroah-Hartman Cc: Mathias Nyman , tiwai@suse.com, regressions@lists.linux.dev, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 03 Dec 2021 16:33:23 +0100 In-Reply-To: References: <35f7428b39f996c793f5b4a6a314772681c73d7a.camel@apache.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2021-12-02 at 16:17 +0100, Greg Kroah-Hartman wrote: > On Thu, Dec 02, 2021 at 03:55:44PM +0100, Robert Munteanu wrote: > > Hi, > > > > After updating from kernel 5.14.11 to 5.14.14 I am seeing the > > following > > problem: > > Can you run 'git bisect' between those kernel versions to get the > offending commit located?  It shouldn't take that long as there's not a > lot of changes there. A full bisect run, as suspected in other messages, results in e54abefe703ab7c4e5983e889babd1447738ca42 is the first bad commit commit e54abefe703ab7c4e5983e889babd1447738ca42 Author: Pavankumar Kondeti Date: Fri Oct 8 12:25:46 2021 +0300 xhci: Fix command ring pointer corruption while aborting a command commit ff0e50d3564f33b7f4b35cadeabd951d66cfc570 upstream. The command ring pointer is located at [6:63] bits of the command ring control register (CRCR). All the control bits like command stop, abort are located at [0:3] bits. While aborting a command, we read the CRCR and set the abort bit and write to the CRCR. The read will always give command ring pointer as all zeros. So we essentially write only the control bits. Since we split the 64 bit write into two 32 bit writes, there is a possibility of xHC command ring stopped before the upper dword (all zeros) is written. If that happens, xHC updates the upper dword of its internal command ring pointer with all zeros. Next time, when the command ring is restarted, we see xHC memory access failures. Fix this issue by only writing to the lower dword of CRCR where all control bits are located. Cc: stable@vger.kernel.org Signed-off-by: Pavankumar Kondeti Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20211008092547.3996295-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman drivers/usb/host/xhci-ring.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) I will try the patch linked by Matias as soon as the openSUSE kernel build is complete. Thanks, Robert