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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D309C46475 for ; Tue, 23 Oct 2018 10:36:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8AE42075D for ; Tue, 23 Oct 2018 10:36:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8AE42075D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727756AbeJWS7D (ORCPT ); Tue, 23 Oct 2018 14:59:03 -0400 Received: from mga05.intel.com ([192.55.52.43]:10724 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727250AbeJWS7D (ORCPT ); Tue, 23 Oct 2018 14:59:03 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Oct 2018 03:36:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,415,1534834800"; d="scan'208";a="273696881" Received: from mattu-haswell.fi.intel.com (HELO [10.237.72.164]) ([10.237.72.164]) by fmsmga005.fm.intel.com with ESMTP; 23 Oct 2018 03:36:11 -0700 Subject: Re: [PATCH 1/2] usb: xhci: fix uninitialized completion when USB3 port got wrong status To: Aaron Ma , mathias.nyman@intel.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <1540141725-13047-1-git-send-email-aaron.ma@canonical.com> <57b1da55-3213-8053-7002-f8798d6e1a10@linux.intel.com> From: Mathias Nyman Message-ID: <8b36fa3a-7999-a2e2-ec01-aa459ec89867@linux.intel.com> Date: Tue, 23 Oct 2018 13:39:43 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22.10.2018 20:53, Aaron Ma wrote: > > > On 10/22/18 9:12 PM, Mathias Nyman wrote: >> On 21.10.2018 20:08, Aaron Ma wrote: >>> Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on >>> Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3, >>> after clear port reset it works fine. >>> >>> Since this device is registered on USB3 roothub at boot, >>> when port status reports not superspeed, xhci_get_port_status will call >>> an uninitialized completion in bus_state[0]. >>> Kernel will hang because of NULL pointer. >>> >>> Restrict the USB2 resume status check in USB2 roothub to fix hang issue. >>> No harm to initialize USB3 bus_state[0] in case it is called. >>> >>> Signed-off-by: Aaron Ma >>> --- >>>   drivers/usb/host/xhci-hub.c  | 2 +- >>>   drivers/usb/host/xhci-mem.c  | 1 >>>   drivers/usb/host/xhci-ring.c | 2 +- >>>   3 files changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c >>> index 7e2a531ba321..d30ca6ceffc9 100644 >>> --- a/drivers/usb/host/xhci-hub.c >>> +++ b/drivers/usb/host/xhci-hub.c >>> @@ -876,7 +876,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd, >>>               status |= USB_PORT_STAT_SUSPEND; >>>       } >>>       if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME && >>> -        !DEV_SUPERSPEED_ANY(raw_port_status)) { >>> +        !DEV_SUPERSPEED_ANY(raw_port_status) && 1 == hcd_index(hcd)) { >>>           if ((raw_port_status & PORT_RESET) || >>>                   !(raw_port_status & PORT_PE)) >>>               return 0xffffffff; >> >> The original !DEV_SUPERSPEED_ANY() check was not suitable here. >> It checks the port-speed field of portsc register (bits 13:10), which >> are only valid for USB3 >> ports if all link training is done and port reached its "enabled" state. >> Otherwise it will return 0, and USB3 ports may be mistaken for USB2 ports. > > PORT_ENABLE should be already set to one. > The same device ID card reader doesn't have issue on Sunrise Point. > Maybe it is related to Cannon lake PCH USB controller? > Ok, thanks for the info > > V2 sent out. Cc-ed stable. > >> Any chance you to check if the refactored code works with the Realtek >> device? >> I just created a "get_port_status_refactor" branch for it: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git >> get_port_status_refactor > > The hang issue is not reproduced on this kernel branch. > Great, thanks for testing it -Mathias