From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751695AbdHOL0w (ORCPT ); Tue, 15 Aug 2017 07:26:52 -0400 Received: from mga07.intel.com ([134.134.136.100]:43557 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbdHOL0v (ORCPT ); Tue, 15 Aug 2017 07:26:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,377,1498546800"; d="scan'208";a="300297620" Subject: Re: [PATCH v3 5/5] usb: xhci: Handle USB transaction error on address command To: Lu Baolu References: <1502419296-8212-1-git-send-email-baolu.lu@linux.intel.com> <1502419296-8212-6-git-send-email-baolu.lu@linux.intel.com> Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, zhengjun.xing@linux.intel.com From: Mathias Nyman Message-ID: <5992DB45.80803@linux.intel.com> Date: Tue, 15 Aug 2017 14:30:13 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <1502419296-8212-6-git-send-email-baolu.lu@linux.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11.08.2017 05:41, Lu Baolu wrote: > Xhci driver handles USB transaction errors on transfer events, > but transaction errors are possible on address device command > completion events as well. > > The xHCI specification (section 4.6.5) says: A USB Transaction > Error Completion Code for an Address Device Command may be due > to a Stall response from a device. Software should issue a Disable > Slot Command for the Device Slot then an Enable Slot Command to > recover from this error. > > This patch handles USB transaction errors on address command > completion events. The related discussion threads can be found > through below links. > > http://marc.info/?l=linux-usb&m=149362010728921&w=2 > http://marc.info/?l=linux-usb&m=149252752825755&w=2 > > Suggested-by: Mathias Nyman > Signed-off-by: Lu Baolu > --- > drivers/usb/host/xhci.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index d6b728d..95780f8 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -3822,6 +3822,11 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev, > break; > case COMP_USB_TRANSACTION_ERROR: > dev_warn(&udev->dev, "Device not responding to setup %s.\n", act); > + > + ret = xhci_disable_slot(xhci, udev->slot_id); > + if (!ret) > + xhci_alloc_dev(hcd, udev); Might be a xhci->mutex locking issue here, both xhci_setup_device() and xhci_alloc_dev() take xhci->mutex -Mathias