From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758597AbcIHJIU (ORCPT ); Thu, 8 Sep 2016 05:08:20 -0400 Received: from mga06.intel.com ([134.134.136.31]:31014 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754534AbcIHJIS (ORCPT ); Thu, 8 Sep 2016 05:08:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,298,1470726000"; d="scan'208";a="876341203" 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> <57D11355.8040505@linux.intel.com> <20160908085819.GA21294@kroah.com> Cc: Mathias Nyman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org From: Lu Baolu Message-ID: <57D12A80.8030402@linux.intel.com> Date: Thu, 8 Sep 2016 17:08:16 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160908085819.GA21294@kroah.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, On 09/08/2016 04:58 PM, Greg KH wrote: > On Thu, Sep 08, 2016 at 03:29:25PM +0800, Lu Baolu wrote: >> 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". > Why didn't you include this in the changelog text so that it is obvious > why this patch is needed? > > Don't just describe what the patch does, we can read C code, describe > _why_ it is needed. Yes. Thank you for the guidance. I will do it in a v3 patch. Best regards, Lu Baolu