From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: [PATCH 1/2] cpufreq: Return error if ->get() failed in cpufreq_update_policy() Date: Fri, 14 Feb 2014 16:30:40 +0530 Message-ID: <15ccc0609cb9ee3db0ad3a95b29bf69d11ea197c.1392375504.git.viresh.kumar@linaro.org> Return-path: Received: from mail-wi0-f179.google.com ([209.85.212.179]:60941 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbaBNLAw (ORCPT ); Fri, 14 Feb 2014 06:00:52 -0500 Received: by mail-wi0-f179.google.com with SMTP id hn9so336862wib.0 for ; Fri, 14 Feb 2014 03:00:51 -0800 (PST) Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: rjw@rjwysocki.net Cc: linaro-kernel@lists.linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, pierre-list@ossman.eu, Viresh Kumar cpufreq_update_policy() calls cpufreq_driver->get() to get current frequency of a CPU and it is not supposed to fail or return zero. Return error in case that happens. Signed-off-by: Viresh Kumar --- Pierre, I don't think this will fix the issue you were facing but might supress it :).. And so you need to understand what causes your ->get() to return zero. @Rafael: I got to these patches while looking at code recently after Pierre complained about. Came to this conclusion after having discussions with Srivatsa over IRC.. drivers/cpufreq/cpufreq.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 08ca8c9..383362b 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2151,6 +2151,13 @@ int cpufreq_update_policy(unsigned int cpu) */ if (cpufreq_driver->get) { new_policy.cur = cpufreq_driver->get(cpu); + + if (!new_policy.cur) { + pr_err("%s: ->get() returned 0 KHz\n", __func__); + ret = -EINVAL; + goto no_policy; + } + if (!policy->cur) { pr_debug("Driver did not initialize current freq"); policy->cur = new_policy.cur; -- 1.7.12.rc2.18.g61b472e