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=-11.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 3785EC4320A for ; Tue, 10 Aug 2021 15:06:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D98360551 for ; Tue, 10 Aug 2021 15:06:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241888AbhHJPGb (ORCPT ); Tue, 10 Aug 2021 11:06:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:46640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231346AbhHJPGa (ORCPT ); Tue, 10 Aug 2021 11:06:30 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CF5A960EE7; Tue, 10 Aug 2021 15:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628607968; bh=dqo+NJskWQkpj9z6N8xQUfDVCUEgPwqRUPQ6njYYZIU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ioa/h9et+21lof64iWcP5IEezko5Fo8Nqs6H05OAupK1dLhs3GN9D51vWnWrbqE5n wT1Wy+cJFuzI5alZMPTwRpfA0mB9YMF/Od757RFP+NeKLfRVrWhgHSe0MNpC5BWscQ BqH5kEV/rpZYKkl8BIlTBkXMHmBLcbnkTqXnC1ck= Date: Tue, 10 Aug 2021 17:06:05 +0200 From: Greg KH To: Prasad Sodagudi Cc: rjw@rjwysocki.net, len.brown@intel.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, pavel@ucw.cz Subject: Re: [PATCH v2] PM: sleep: core: Avoid setting power.must_resume to false Message-ID: References: <1628602932-246733-1-git-send-email-psodagud@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1628602932-246733-1-git-send-email-psodagud@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 10, 2021 at 06:42:11AM -0700, Prasad Sodagudi wrote: > This is regarding suspend/resume(s2idle) scenario of devices and difference > between the LTS kernels 5.4 and 5.10 with respect to devices suspend and > resume. Observing that devices suspended in suspend_late stage are not > getting resumed in resume_early stage. > 1) LTS kernel 5.4 kernel do not have this problem but 5.10 kernel > shows this problem. > 2) 'commit 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase")' > is skipping the driver early_resume callbacks. > > In device_resume_early function dev->power.must_resume is used to skip the > resume call back. It looks this function is expecting that, > __device_suspend_noirq() would set dev->power.must_resume = true for the > devices which does not have DPM_FLAG_MAY_SKIP_RESUME flag set. > > 3) Problematic scenario is as follows - During the device suspend/resume > scenario all the devices in the suspend_late stage are successful and some > device can fail to suspend in suspend_noirq(device_suspend_noirq-> > __device_suspend_noirq) phase. > As a device failed in dpm_noirq_suspend_devices phase, dpm_resume_noirq is > getting called to resume devices in dpm_late_early_list in the noirq phase. > > 4) During the Devices_early_resume stage > dpm_resume_early()-->device_resume_early() functions skipping the devices > early resume callbacks. > 799 if (dev_pm_skip_resume(dev)) > 800 goto Skip; > > 5) Devices suspended in suspend_late stage are not getting resumed in > Devices_early_resume stage because of > 'commit 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase")' > is skipping the driver early_resume callbacks when dev->power.must_resume is false. > > > Changelog: > v1 -> v2: > - Fixed indentation comments. > - Commit text updated to include scenario. > > Prasad Sodagudi (1): > PM: sleep: core: Avoid setting power.must_resume to false > > drivers/base/power/main.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project > I do not see a patch here, what happened? :(