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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 7E923C433E0 for ; Sat, 27 Mar 2021 10:49:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45680619E8 for ; Sat, 27 Mar 2021 10:49:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231304AbhC0Ktj (ORCPT ); Sat, 27 Mar 2021 06:49:39 -0400 Received: from comms.puri.sm ([159.203.221.185]:37894 "EHLO comms.puri.sm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229883AbhC0Kti (ORCPT ); Sat, 27 Mar 2021 06:49:38 -0400 Received: from localhost (localhost [127.0.0.1]) by comms.puri.sm (Postfix) with ESMTP id C484FDF73C; Sat, 27 Mar 2021 03:49:03 -0700 (PDT) Received: from comms.puri.sm ([127.0.0.1]) by localhost (comms.puri.sm [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nqox2EnRN_Jd; Sat, 27 Mar 2021 03:49:02 -0700 (PDT) Message-ID: <9d0042fbfba9d33315f9eee7448b60aca8949431.camel@puri.sm> Subject: Re: [PATCH v2 0/3] scsi: add runtime PM workaround for SD cardreaders From: Martin Kepplinger To: jejb@linux.ibm.com, martin.petersen@oracle.com, stern@rowland.harvard.edu, bvanassche@acm.org Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sat, 27 Mar 2021 11:48:57 +0100 In-Reply-To: <20210112093329.3639-1-martin.kepplinger@puri.sm> References: <20210112093329.3639-1-martin.kepplinger@puri.sm> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.3-1 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, dem 12.01.2021 um 10:33 +0100 schrieb Martin Kepplinger: > revision history > ---------------- > v2: >  * move module parameter to sd >  * add Documentation > > v1: > https://lore.kernel.org/linux-scsi/20210111152029.28426-1-martin.kepplinger@puri.sm/T/#t > > > > hi, > > In short: there are SD cardreaders that send MEDIA_CHANGED on > runtime resume. We cannot use runtime PM with these devices as > I/O basically always fails. I'd like to discuss a way to fix this > or at least allow users to work around this problem: > > For the full background, the discussion started in June 2020 here: > https://lore.kernel.org/linux-scsi/20200623111018.31954-1-martin.kepplinger@puri.sm/ > > and I sent the first of these patches in August, as a reference: > https://lore.kernel.org/linux-scsi/20200824190400.12339-1-martin.kepplinger@puri.sm/ > so this is where I'm following up on. > > I'm not sure whether maintaining an in-kernel quirk for specific > devices > makes sense so here I suggest adding a userspace knob. This way > there's at > least a chance to use runtime PM for sd cardreaders that send > MEDIA_CHANGED. > > I'd appreciate any feedback. > > Martin Kepplinger (3): >   scsi: add expecting_media_change flag to error path >   scsi: sd: add ignore_resume_medium_changed disk setting >   scsi: sd: Documentation: describe ignore_resume_medium_changed > >  Documentation/scsi/sd-parameters.rst | 14 ++++++++ >  drivers/scsi/scsi_error.c            | 36 +++++++++++++++++--- >  drivers/scsi/sd.c                    | 50 > +++++++++++++++++++++++++++- >  drivers/scsi/sd.h                    |  1 + >  include/scsi/scsi_device.h           |  1 + >  5 files changed, 96 insertions(+), 6 deletions(-) > hi James, Bart and all, since this is absolutely needed for runtime pm with the SD device we use I assume there are others that would benefit from this too. Do you have any concerns or thoughts about this (logic and interface)? the patches still apply. thanks a lot, martin