From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH] PM / Runtime: Defer resuming of the device in pm_runtime_force_resume() Date: Thu, 12 May 2016 22:01:13 +0300 Message-ID: <4661739.p5SU9QcIps@avalon> References: <1461234842-22820-1-git-send-email-ulf.hansson@linaro.org> <5465506.Z3sjI0lQh6@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from galahad.ideasonboard.com ([185.26.127.97]:50534 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752303AbcELTBQ (ORCPT ); Thu, 12 May 2016 15:01:16 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Ulf Hansson Cc: "Rafael J. Wysocki" , "linux-pm@vger.kernel.org" , Alan Stern , Kevin Hilman , Len Brown , Pavel Machek , Lina Iyer , Andy Gross , Linus Walleij , Sergei Shtylyov , "linux-arm-kernel@lists.infradead.org" Hello, On Wednesday 27 Apr 2016 16:23:49 Ulf Hansson wrote: > [...] > > >> Following you reasoning, I agree! > >> > >> Let's put this patch on hold for a little while. I am already working > >> on changing genpd, so it shouldn't take long before I can post some > >> additional genpd patches improving the behaviour. > > > > I'd like to see something merged for v4.7 if possible. I agree that my > > patch isn't a long term solution (we want to avoid adding additional > > fields to the device power structure), but it has the benefit of being > > available now and fixing the problem I ran into with drivers that would > > be broken on v4.7 without a fix. Do you think you could get a better fix > > ready in time for v4.7 ? If so I'm fine with dropping this patch, but > > otherwise I'd prefer to get it merged and reverted as part of your better > > implementation for v4.8. > > My impression was that devices becomes unnecessary resumed when they > don't need to. They won't stay resumed as the PM core invokes > pm_runtime_put() in the system PM complete phase. > > So, in the end I think we are trying to optimize a behaviour here, but > not fix something that is "broken", correct? > > Anyway, I have no objections to your proposed solution, so I leave it > to Rafael and Kevin to decide what to do. Kevin, Rafael, any comment ? I need to fix PM support in a driver that is currently broken partly due to this issue. Which of "PM / Runtime: Only force- resume device if it has been force-suspended" and this patch should we merge, if any ? > From my side I will continue with the improvements for the system PM > support in genpd. Thanks. -- Regards, Laurent Pinchart From mboxrd@z Thu Jan 1 00:00:00 1970 From: laurent.pinchart@ideasonboard.com (Laurent Pinchart) Date: Thu, 12 May 2016 22:01:13 +0300 Subject: [PATCH] PM / Runtime: Defer resuming of the device in pm_runtime_force_resume() In-Reply-To: References: <1461234842-22820-1-git-send-email-ulf.hansson@linaro.org> <5465506.Z3sjI0lQh6@avalon> Message-ID: <4661739.p5SU9QcIps@avalon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On Wednesday 27 Apr 2016 16:23:49 Ulf Hansson wrote: > [...] > > >> Following you reasoning, I agree! > >> > >> Let's put this patch on hold for a little while. I am already working > >> on changing genpd, so it shouldn't take long before I can post some > >> additional genpd patches improving the behaviour. > > > > I'd like to see something merged for v4.7 if possible. I agree that my > > patch isn't a long term solution (we want to avoid adding additional > > fields to the device power structure), but it has the benefit of being > > available now and fixing the problem I ran into with drivers that would > > be broken on v4.7 without a fix. Do you think you could get a better fix > > ready in time for v4.7 ? If so I'm fine with dropping this patch, but > > otherwise I'd prefer to get it merged and reverted as part of your better > > implementation for v4.8. > > My impression was that devices becomes unnecessary resumed when they > don't need to. They won't stay resumed as the PM core invokes > pm_runtime_put() in the system PM complete phase. > > So, in the end I think we are trying to optimize a behaviour here, but > not fix something that is "broken", correct? > > Anyway, I have no objections to your proposed solution, so I leave it > to Rafael and Kevin to decide what to do. Kevin, Rafael, any comment ? I need to fix PM support in a driver that is currently broken partly due to this issue. Which of "PM / Runtime: Only force- resume device if it has been force-suspended" and this patch should we merge, if any ? > From my side I will continue with the improvements for the system PM > support in genpd. Thanks. -- Regards, Laurent Pinchart