From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com ([134.134.136.24]:27173 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757152AbcIHH3b (ORCPT ); Thu, 8 Sep 2016 03:29:31 -0400 Subject: Re: [PATCH v2 1/1] usb: xhci: fix return value of xhci_setup_device() To: Greg KH References: <1473295302-3956-1-git-send-email-baolu.lu@linux.intel.com> <20160908063828.GA5485@kroah.com> Cc: Mathias Nyman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org From: Lu Baolu Message-ID: <57D11355.8040505@linux.intel.com> Date: Thu, 8 Sep 2016 15:29:25 +0800 MIME-Version: 1.0 In-Reply-To: <20160908063828.GA5485@kroah.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: Hi Greg, On 09/08/2016 02:38 PM, Greg KH wrote: > On Thu, Sep 08, 2016 at 08:41:02AM +0800, Lu Baolu wrote: >> xhci_setup_device() should return failure with correct error number >> when xhci host has died, removed or halted. >> >> Cc: stable@vger.kernel.org # 4.3+ > Why is this a stable kernel issue? What bug does it fix that affects > users? During usb device enumeration, if xhci host is not accessible (died, removed or halted), the hc_driver->address_device() should return a corresponding error code to usb core. But current xhci driver just returns success. This will mislead usb core to continue enumeration: reading device descriptor, which will result in failure, and users will get a misleading message like "device descriptor read/8, error -110". Best regards, Lu Baolu