Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753350Ab1FRX5G (ORCPT ); Sat, 18 Jun 2011 19:57:06 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:39142 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753058Ab1FRX5E (ORCPT ); Sat, 18 Jun 2011 19:57:04 -0400 From: "Rafael J. Wysocki" To: Alan Stern Subject: Re: [linux-pm] calling runtime PM from system PM methods Date: Sun, 19 Jun 2011 01:57:31 +0200 User-Agent: KMail/1.13.6 (Linux/3.0.0-rc3+; KDE/4.6.0; x86_64; ; ) Cc: linux-pm@lists.linux-foundation.org, linux-omap@vger.kernel.org, Kevin Hilman , Paul Walmsley , Magnus Damm , LKML References: <201106182301.04090.rjw@sisk.pl> In-Reply-To: <201106182301.04090.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201106190157.31526.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2967 Lines: 89 On Saturday, June 18, 2011, Rafael J. Wysocki wrote: > On Saturday, June 18, 2011, Alan Stern wrote: > > On Sat, 18 Jun 2011, Rafael J. Wysocki wrote: ... > > Well, assuming that https://patchwork.kernel.org/patch/893722/ is applied, > which is going to be, I think we can put > > + pm_runtime_get_noresume(dev); > + pm_runtime_enable(dev); > > in device_resume() after the dev->power.is_suspended check and > pm_runtime_put_noidle() under the End label. That cause them to > be called under the device lock, but that shouldn't be a big deal. > > Accordingly, we can call pm_runtime_disable(dev) in __device_suspend(), > right next to the setting of power.is_suspended. > > This is implemented by the patch below. Well, it hangs suspend on my Toshiba test box, I'm not sure why exactly. This happens even if the pm_runtime_disable() is replaced with a version that only increments the disable depth, so it looks like something down the road relies on disable_depth being zero. Which is worrisome. Trying to figure out what the problem is I noticed that, for example, the generic PM operations use pm_runtime_suspended() to decide whether or not to execute system suspend callbacks, so the patch below would break it. Also, after commit e8665002477f0278f84f898145b1f141ba26ee26 the pm_runtime_suspended() check in __pm_generic_call() doesn't really make sense. Thanks, Rafael > --- > drivers/base/power/main.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > Index: linux-2.6/drivers/base/power/main.c > =================================================================== > --- linux-2.6.orig/drivers/base/power/main.c > +++ linux-2.6/drivers/base/power/main.c > @@ -521,6 +521,9 @@ static int device_resume(struct device * > if (!dev->power.is_suspended) > goto Unlock; > > + pm_runtime_get_noresume(dev); > + pm_runtime_enable(dev); > + > if (dev->pwr_domain) { > pm_dev_dbg(dev, state, "power domain "); > error = pm_op(dev, &dev->pwr_domain->ops, state); > @@ -557,6 +560,7 @@ static int device_resume(struct device * > > End: > dev->power.is_suspended = false; > + pm_runtime_put_noidle(dev); > > Unlock: > device_unlock(dev); > @@ -888,7 +892,10 @@ static int __device_suspend(struct devic > } > > End: > - dev->power.is_suspended = !error; > + if (!error) { > + dev->power.is_suspended = true; > + pm_runtime_disable(dev); > + } > > Unlock: > device_unlock(dev); > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/