From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH 1/2] cpufreq: arm_big_little: check if the frequency is set correctly Date: Fri, 15 May 2015 02:20:36 +0200 Message-ID: <1778706.Xlqg2QcRzz@vostro.rjw.lan> References: <1430128266-15012-1-git-send-email-sudeep.holla@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from v094114.home.net.pl ([79.96.170.134]:54921 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1423067AbbENXzX (ORCPT ); Thu, 14 May 2015 19:55:23 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: Sudeep Holla , Linux Kernel Mailing List , "linux-pm@vger.kernel.org" On Monday, April 27, 2015 03:56:18 PM Viresh Kumar wrote: > On 27 April 2015 at 15:21, Sudeep Holla wrote: > > The actual frequency is set through "clk_change_rate" which is void > > function. If the underlying hardware fails and returns error, the error > > is lost in the clk layer. In order to track such failures, we need to > > read back the frequency(just the cached value as clk_recalc called after > > clk->ops->set_rate gets the frequency) > > > > This patch adds check to see if the frequency is set correctly or if > > they were any hardware failures and sends the appropriate errors to the > > cpufreq core. > > > > Cc: Viresh Kumar > > Reviewed-by: Michael Turquette > > Signed-off-by: Sudeep Holla > > --- > > drivers/cpufreq/arm_big_little.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c > > index e1a6ba66a7f5..f65e19f340d0 100644 > > --- a/drivers/cpufreq/arm_big_little.c > > +++ b/drivers/cpufreq/arm_big_little.c > > @@ -186,6 +186,15 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate) > > mutex_unlock(&cluster_lock[old_cluster]); > > } > > > > + /* > > + * FIXME: clk_set_rate has to handle the case where clk_change_rate > > + * can fail due to hardware or firmware issues. Until the clk core > > + * layer is fixed, we can check here. In most of the cases we will > > + * be reading only the cached value anyway. This needs to be removed > > + * once clk core is fixed. > > + */ > > + if (bL_cpufreq_get_rate(cpu) != new_rate) > > + return -EIO; > > return 0; > > } > > Acked-by: Viresh Kumar Both queued up for 4.2, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.