From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Srivatsa S. Bhat" , "Rafael J. Wysocki" Subject: [ 18/19] cpufreq: Fix cpufreq regression after suspend/resume Date: Thu, 11 Jul 2013 15:01:35 -0700 Message-Id: <20130711214832.686008000@linuxfoundation.org> In-Reply-To: <20130711214830.611455274@linuxfoundation.org> References: <20130711214830.611455274@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Srivatsa S. Bhat" commit f51e1eb63d9c28cec188337ee656a13be6980cfd upstream. Toralf Förster reported that the cpufreq ondemand governor behaves erratically (doesn't scale well) after a suspend/resume cycle. The problem was that the cpufreq subsystem's idea of the cpu frequencies differed from the actual frequencies set in the hardware after a suspend/resume cycle. Toralf bisected the problem to commit a66b2e5 (cpufreq: Preserve sysfs files across suspend/resume). Among other (harmless) things, that commit skipped the call to cpufreq_update_policy() in the resume path. But cpufreq_update_policy() plays an important role during resume, because it is responsible for checking if the BIOS changed the cpu frequencies behind our back and resynchronize the cpufreq subsystem's knowledge of the cpu frequencies, and update them accordingly. So, restore the call to cpufreq_update_policy() in the resume path to fix the cpufreq regression. Reported-and-tested-by: Toralf Förster Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/cpufreq/cpufreq_stats.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -349,6 +349,7 @@ static int __cpuinit cpufreq_stat_cpu_ca switch (action) { case CPU_ONLINE: + case CPU_ONLINE_FROZEN: cpufreq_update_policy(cpu); break; case CPU_DOWN_PREPARE: