From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757414Ab1CAUXF (ORCPT ); Tue, 1 Mar 2011 15:23:05 -0500 Received: from www.tglx.de ([62.245.132.106]:41443 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757148Ab1CAUXD (ORCPT ); Tue, 1 Mar 2011 15:23:03 -0500 Date: Tue, 1 Mar 2011 21:22:46 +0100 (CET) From: Thomas Gleixner To: Seth Forshee cc: Len Brown , Linux Kernel Mailing List , "H. Peter Anvin" , Arjan van de Ven , Venkatesh Pallipadi Subject: Re: Performance/resume issues on Toshiba NB305 In-Reply-To: <20110301200446.GA2235@thinkpad-t410> Message-ID: References: <20110225164239.GA24686@thinkpad-t410> <20110225212142.GC24686@thinkpad-t410> <20110301200446.GA2235@thinkpad-t410> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Mar 2011, Seth Forshee wrote: > On Fri, Feb 25, 2011 at 10:47:16PM +0100, Thomas Gleixner wrote: > > On Fri, 25 Feb 2011, Seth Forshee wrote: > > > On Fri, Feb 25, 2011 at 09:37:39PM +0100, Thomas Gleixner wrote: > > > > On Fri, 25 Feb 2011, Seth Forshee wrote: > > > > That seems to be related to low power states. When the machine goes > > > > idle we switch into lower power states and that requires to use the > > > > hpet instead of the local apic timer as that one stops. > > > > > > > > You could verify that theory by booting with processor.max_cstate=1 > > > > > > This fixes the performance in combination with intel_idle.max_cstate=0. > > > Alternately, intel_idle.max_cstate=1 works. But the resume still hangs. > > > > That was expected :) > > > > > Is the answer to quirk the machine to avoid deep C-states, or is there > > > some better way I can fix this? > > > > Let's wait for the intel and acpi folks. It would be interesting what > > the new intel toy says to your BIOS. > > Since the discussion on this issue died without really getting anywhere, > I went ahead and threw together the patch below to disable anything > deeper than C1 for this machine. I hope a better solution can be found, > but if not would something like this be an acceptable workaround? > > As for the hangs during resume, unless someone has a better suggestion I > guess I'll start looking into forcing the HPET to remain in periodic > mode throughout suspend. The problem with such DMI quirks is that it's hard to get rid of them when a fixed BIOS version comes out while simply adding nohpet to the kernel command line, is a non permanent, but sensible workaround. Thanks, tglx