Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752840Ab3IKIox (ORCPT ); Wed, 11 Sep 2013 04:44:53 -0400 Received: from mail-qe0-f46.google.com ([209.85.128.46]:44349 "EHLO mail-qe0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432Ab3IKIov (ORCPT ); Wed, 11 Sep 2013 04:44:51 -0400 MIME-Version: 1.0 In-Reply-To: <1378883105-1411-1-git-send-email-tianyu.lan@intel.com> References: <1378883105-1411-1-git-send-email-tianyu.lan@intel.com> Date: Wed, 11 Sep 2013 14:14:50 +0530 Message-ID: Subject: Re: [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock From: Viresh Kumar To: Lan Tianyu Cc: "Rafael J. Wysocki" , "Srivatsa S. Bhat" , "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1432 Lines: 37 On 11 September 2013 12:35, wrote: > From: Lan Tianyu > > In the cpufreq_policy_restore(), policy before system suspend is read from > from percpu's cpufreq_cpu_data_fallback. It's read operation rather than > write operation. So convert write lock to read lock > > Signed-off-by: Lan Tianyu > --- > drivers/cpufreq/cpufreq.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 81ceea6..b762f9b 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -912,11 +912,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) > struct cpufreq_policy *policy; > unsigned long flags; > > - write_lock_irqsave(&cpufreq_driver_lock, flags); > + read_lock_irqsave(&cpufreq_driver_lock, flags); > > policy = per_cpu(cpufreq_cpu_data_fallback, cpu); > > - write_unlock_irqrestore(&cpufreq_driver_lock, flags); > + read_unlock_irqrestore(&cpufreq_driver_lock, flags); > > return policy; > } Acked-by: Viresh Kumar -- 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/