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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,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 0A631C432BE for ; Fri, 27 Aug 2021 08:58:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E31BA608FE for ; Fri, 27 Aug 2021 08:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244604AbhH0I7H (ORCPT ); Fri, 27 Aug 2021 04:59:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:50250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232757AbhH0I6y (ORCPT ); Fri, 27 Aug 2021 04:58:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2120A608FE; Fri, 27 Aug 2021 08:58:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1630054685; bh=77yL8U8+buC1Srr5lcXcqgg1GZ5TiZMsD9z6Pe25ohA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FTvx7NUb9j2WXBbHdWdpnh2el917e6I0ArcOvvSYF8r1z0T0HXm6sZIewdkoJR6LL HSJWk6TB5jjO8Xkvr+BYQNG28Zim2EMSHT2eMy/BR1uoWG7ks9FAtuFYrncU9lbySe 4oKkWzKTSxfmoUalOhYOB9mNN2tBYcEn7vZdgxhQ= Date: Fri, 27 Aug 2021 10:57:59 +0200 From: Greg KH To: Prasad Sodagudi , rjw@rjwysocki.net Cc: len.brown@intel.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, pavel@ucw.cz Subject: Re: [PATCH v4] PM: sleep: core: Avoid setting power.must_resume to false Message-ID: References: <1629732470-155444-1-git-send-email-psodagud@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1629732470-155444-1-git-send-email-psodagud@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 23, 2021 at 08:27:50AM -0700, Prasad Sodagudi wrote: > There are variables(power.may_skip_resume and dev->power.must_resume) > and DPM_FLAG_MAY_SKIP_RESUME flags to control the resume of devices after > a system wide suspend transition. > > Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver allows > its "noirq" and "early" resume callbacks to be skipped if the device > can be left in suspend after a system-wide transition into the working > state. PM core determines that the driver's "noirq" and "early" resume > callbacks should be skipped or not with dev_pm_skip_resume() function by > checking power.may_skip_resume variable. > > power.must_resume variable is getting set to false in __device_suspend() > function without checking device's DPM_FLAG_MAY_SKIP_RESUME settings. > In problematic scenario, where all the devices in the suspend_late > stage are successful and some device can fail to suspend in > suspend_noirq phase. So some devices successfully suspended in suspend_late > stage are not getting chance to execute __device_suspend_noirq() > to set dev->power.must_resume variable to true and not getting > resumed in early_resume phase. > > Add a check for device's DPM_FLAG_MAY_SKIP_RESUME flag before > setting power.must_resume variable in __device_suspend function. > > Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase") > Signed-off-by: Prasad Sodagudi > --- > V3 -> V4: Remove dev->power.usage_count variable check > V2 -> V3: Format issues patch posting > V1 -> V2: Fixed indentation and commit text to include scenario > drivers/base/power/main.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index d568772..50e8ea3 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -1642,7 +1642,10 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) > } > > dev->power.may_skip_resume = true; > - dev->power.must_resume = false; > + if (dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME)) > + dev->power.must_resume = false; > + else > + dev->power.must_resume = true; > > dpm_watchdog_set(&wd, dev); > device_lock(dev); Seems sane, Rafael, any comments? thanks, greg k-h