From mboxrd@z Thu Jan 1 00:00:00 1970 From: rosslagerwall@gmail.com Subject: Re: [stable request <=3.7] acpi-cpufreq: set current frequency based on target P-State Date: Wed, 26 Mar 2014 07:22:32 +0000 Message-ID: <20140326072232.GA777@hobo.lan> References: <20131220081912.GA13684@hobo.Home> <1395785057-28903-1-git-send-email-vlee@twopensource.com> <20140325221803.GA32518@hobo.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from mail-we0-f179.google.com ([74.125.82.179]:36947 "EHLO mail-we0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752108AbaCZHW1 (ORCPT ); Wed, 26 Mar 2014 03:22:27 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Vinson Lee Cc: stable@vger.kernel.org, "Rafael J. Wysocki" , Viresh Kumar , cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, Len Brown , "Rafael J. Wysocki" , Shatil Rafiullah On Tue, Mar 25, 2014 at 03:53:40PM -0700, Vinson Lee wrote: > On Tue, Mar 25, 2014 at 3:18 PM, wrote: > > On Tue, Mar 25, 2014 at 03:04:16PM -0700, Vinson Lee wrote: > >> Hi. > >> > >> Please backport upstream commit 8673b83bf2f013379453b4779047bf3c6ae387e4 > >> "acpi-cpufreq: set current frequency based on target P-State" to stable > >> kernels 3.7 and earlier. This patch enables the kernel to control > >> P-states on several platforms. Without this patch, the kernel was unable > >> to control P-states on the same platforms. > >> > >> The upstream patch cleanly applies to 3.7. > >> > >> A backported patch is needed with the removal of SYSTEM_AMD_MSR_CAPABLE > >> for kernels 3.6 and earlier. > >> > > > > I seem to recall that the problem was a regression introduced by commit > > 5a1c0228 (cpufreq: Avoid calling cpufreq driver's target() routine if > > target_freq == policy->cur) which was introduced in the 3.8 cycle. Are > > you sure it is necessary for kernels < 3.8? > > > > Regards > > -- > > Ross Lagerwall > > > This specific patch allows P-states to work with the 3.4 kernel on > several hardware platforms. > > Perhaps this is not the correct patch to backport. However, P-states > are not working properly with the 3.4 kernel, even though it does not > have the regression commit 5a1c0228 "cpufreq: Avoid calling cpufreq > driver's target() routine if target_freq == policy->cur" backported. > Fair enough, Cheers -- Ross Lagerwall