Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758036AbZGJXrl (ORCPT ); Fri, 10 Jul 2009 19:47:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757436AbZGJXrc (ORCPT ); Fri, 10 Jul 2009 19:47:32 -0400 Received: from mx2.redhat.com ([66.187.237.31]:48624 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757388AbZGJXrb (ORCPT ); Fri, 10 Jul 2009 19:47:31 -0400 Date: Fri, 10 Jul 2009 19:46:47 -0400 From: Dave Jones To: Benjamin Herrenschmidt Cc: Marcin Slusarz , LKML , Linux PM List , cpufreq@vger.kernel.org Subject: Re: 2.6.31-rc2+: Interrupts enabled after cpufreq_suspend Message-ID: <20090710234646.GA11669@redhat.com> Mail-Followup-To: Dave Jones , Benjamin Herrenschmidt , Marcin Slusarz , LKML , Linux PM List , cpufreq@vger.kernel.org References: <4A561074.5080407@gmail.com> <20090710192511.GB6240@redhat.com> <1247264617.21776.6.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1247264617.21776.6.camel@pasglop> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1841 Lines: 45 On Sat, Jul 11, 2009 at 08:23:37AM +1000, Ben Herrenschmidt wrote: > On Fri, 2009-07-10 at 15:25 -0400, Dave Jones wrote: > > > The answer seems to be in 42d4dc3f4e1ec1396371aac89d0dccfdd977191b > > which introduced all this code to work around some failure that only happens > > on PPC... > > > > [PATCH] Add suspend method to cpufreq core > > > > In order to properly fix some issues with cpufreq vs. sleep on > > PowerBooks, I had to add a suspend callback to the pmac_cpufreq driver. > > I must force a switch to full speed before sleep and I switch back to > > previous speed on resume. > > > > > > Ben, is there something better we can do here ? > > > > I really don't want to add an #ifdef __powerpc__ to core code if we can help it. > > I'd rather we didn't call into driver guts at all from the suspend path. > > Wait a minute ... having a suspend/resume method in cpufreq is one > thing, having it muck around with SMP is another :-) The ppc code > doesn't do that. > > There's nothing fundamentally "fail" in requiring a switch to a given > frequency before suspend. I don't know what kind of major FAIL the K8 > code is doing here though :-) The fail part comes from the fact that interrupts get reenabled. And that's something that can easily happen out of our control if we call into acpi_cpufreq's ->get method for example, so powernow-k8 isn't the sole reason. > I'm happy instead of #ifdef's however to push the logic into the ppc > driver, or use a flag that the ppc driver sets to enable that logic. Cool. Dave -- 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/