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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 139F1C4363A for ; Wed, 21 Oct 2020 20:11:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBAE424181 for ; Wed, 21 Oct 2020 20:11:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2505117AbgJUUL3 (ORCPT ); Wed, 21 Oct 2020 16:11:29 -0400 Received: from netrider.rowland.org ([192.131.102.5]:49731 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S2438854AbgJUUL3 (ORCPT ); Wed, 21 Oct 2020 16:11:29 -0400 Received: (qmail 1003433 invoked by uid 1000); 21 Oct 2020 16:11:27 -0400 Date: Wed, 21 Oct 2020 16:11:27 -0400 From: Alan Stern To: Bastien Nocera Cc: "M. Vefa Bicakci" , Pany , linux-usb@vger.kernel.org Subject: Re: Bug caused by 53965c79c2db (USB: Fix device driver race) Message-ID: <20201021201127.GA1002979@rowland.harvard.edu> References: <20201017200200.GB842001@rowland.harvard.edu> <20201019174028.GF898631@rowland.harvard.edu> <20201020152859.GA945128@rowland.harvard.edu> <74e25095-53fa-b98c-6baf-c97eea574d1c@runbox.com> <83bd4ab7-15a6-73c2-decd-1da1c393bad0@runbox.com> <5d2dc161951d0717d1ccfc88049c241c8ce8d1e6.camel@hadess.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5d2dc161951d0717d1ccfc88049c241c8ce8d1e6.camel@hadess.net> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Oct 21, 2020 at 03:18:06PM +0200, Bastien Nocera wrote: > On Wed, 2020-10-21 at 09:08 -0400, M. Vefa Bicakci wrote: > > On 21/10/2020 07.53, Bastien Nocera wrote: > > [Snipped by Vefa] > > > > > > I have no idea why there isn't a match function. Patch v1 had a > > > huge > > > table: > > > https://marc.info/?l=linux-usb&m=157062863431186&w=2 > > > and v2 already didn't had that comment, but no .match function: > > > https://marc.info/?l=linux-usb&m=157114990905421&w=2 > > > > > > I'll prepare a patch that adds a match function. I'll let you > > > (Vefa) > > > look at which of your patches need backporting though, as I'm > > > really > > > quite a bit lost in the different patch sets and branches :/ > > > > Hello Bastien, > > > > Having found the root cause of the issue by going through Pany's > > logs and having proposed a solution, I was hoping to get credit > > for the resolution of the issue by authoring the patch. > > I don't care either way. Attached are the 2 patches I had made and was > in the process of compiling and testing, feel free to adapt them, > change the authorship, etc. > > Note that you mentioned you'd need to "replace the ID table with > a match function", which will mean that the driver isn't automatically > loaded when a device gets plugged in. So that wouldn't have worked. > > Let me know when you've made your patch, as I'll need to update this > bug when there's something to test: > https://bugzilla.redhat.com/show_bug.cgi?id=1878347 > > Cheers > From 6652af5b46f39d9690d72dc11902b36a44c242a1 Mon Sep 17 00:00:00 2001 > From: Bastien Nocera > Date: Wed, 21 Oct 2020 14:31:58 +0200 > Subject: [PATCH 2/2] USB: apple-mfi-fastcharge: don't probe unhandled devices > > Contrary to the comment above the id table, we didn't implement a match > function. This meant that every single Apple device that was already > plugged in to the computer would have its device driver reprobed > when the apple-mfi-fastcharge driver was loaded, eg. the SD card reader > could be reprobed when the apple-mfi-fastcharge after pivoting root > during boot up and the module became available. > > Make sure that the driver probe isn't being run for unsupported > devices by adding a match function that checks the product ID, in > addition to the id_table checking the vendor ID. > > Fixes: 249fa8217b84 ("USB: Add driver to control USB fast charge for iOS devices") > Signed-off-by: Bastien Nocera > --- Another note: The patch description should include a pointer to Pany's RedHat Bugzilla bug report. Alan Stern