From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [RFC][PATCH 2/3] PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily Date: Thu, 15 May 2014 14:55:49 +0200 Message-ID: <1798774.vz7tFfDHW5@vostro.rjw.lan> References: <16671603.abrivY8Odm@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from v094114.home.net.pl ([79.96.170.134]:64627 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751764AbaEOMjB (ORCPT ); Thu, 15 May 2014 08:39:01 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Ulf Hansson Cc: Alan Stern , Linux PM list , ACPI Devel Maling List , Aaron Lu , Mika Westerberg , Linux Kernel Mailing List , Kevin Hilman On Thursday, May 15, 2014 02:06:59 PM Ulf Hansson wrote: > > Do we want to allow ->prepare() to return > 0 if the device isn't > > runtime suspended? If we do then non-suspended devices may be a common > > case. We should then avoid the extra overhead of disable + enable. > > So I would write: > > > > if (dev->power.direct_complete) { > > if (pm_runtime_status_suspended(dev)) { > > pm_runtime_disable(dev); > > if (dev->power.disable_depth == 1 > > && pm_runtime_status_suspended(dev)) > > goto Complete; > > pm_runtime_enable(dev); > > } > > dev->power.direct_complete = false; > > } > > > > I am wondering whether the above pm_runtime_disable|enable actually > belongs better in driver/subsystem in favour of the PM core? No, it doesn't. > Doesn't the driver/subsystem anyway needs to be on top of what goes > on? Typically, while runtime PM has been disabled, that might affect > it's wakeup handling? Or this case are already handled due to other > circumstances? Yes, that's the case. Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.