From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH v2] cpufreq: arm_big_little: fix frequency check when bL switcher is active Date: Wed, 21 Oct 2015 15:27:25 +0530 Message-ID: <20151021095725.GA7784@ubuntu> References: <1445421333.2916.13.camel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:36109 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753883AbbJUJ5a (ORCPT ); Wed, 21 Oct 2015 05:57:30 -0400 Received: by pacfv9 with SMTP id fv9so52700134pac.3 for ; Wed, 21 Oct 2015 02:57:30 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1445421333.2916.13.camel@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Jon Medhurst (Tixy)" Cc: Sudeep Holla , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Turquette On 21-10-15, 10:55, Jon Medhurst (Tixy) wrote: > The check for correct frequency being set in bL_cpufreq_set_rate is > broken when the big.LITTLE switcher is active, for two reasons. > > 1. The 'new_rate' variable gets overwritten before the test by the > code calculating the frequency of the old cluster. > > 2. The frequency returned by bL_cpufreq_get_rate will be the virtual > frequency, not the actual one the intended version of new_rate contains. > > This means the function always returns an error causing an endless > stream of: "cpufreq: __target_index: Failed to change cpu frequency: -5" > > As the intent is to check for errors that clk_set_rate doesn't report > lets move the check to immediately after that and directly use > clk_get_rate, rather than the arm_big_little helpers which only confuse > matters. Also, update the comment to be hopefully clearer about the > purpose of the code. > > Fixes: 0a95e630b49a ("cpufreq: arm_big_little: check if the frequency is set correctly") > > Signed-off-by: Jon Medhurst > Acked-by: Sudeep Holla > --- > > Changes since V1: > - Check rate using clk_get_rate rather than disabling check when bL > switcher active > > Sudeep, I added your Ack from the last comment on the previous patch. > This final patch differs from what was discussed only in the commit > message and in source comment which is hopefully more clear and is > also satisfactory. > > I've also added Michael Turquette's correct email to the CC this time, > rather than his old Linaro address which was bouncing. > > drivers/cpufreq/arm_big_little.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > Acked-by: Viresh Kumar -- viresh