Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932823AbaD1T0D (ORCPT ); Mon, 28 Apr 2014 15:26:03 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:34261 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932769AbaD1T0A (ORCPT ); Mon, 28 Apr 2014 15:26:00 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH v2 4/5] cpufreq, powernow-k7: Fix double invocation of cpufreq_freq_transition_begin/end To: rjw@rjwysocki.net, mroos@linux.ee, viresh.kumar@linaro.org Cc: cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com Date: Tue, 29 Apr 2014 00:24:58 +0530 Message-ID: <20140428185451.28755.11924.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20140428185331.28755.899.stgit@srivatsabhat.in.ibm.com> References: <20140428185331.28755.899.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14042818-1396-0000-0000-000004C0BC5A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org During frequency transitions, the cpufreq core takes the responsibility of invoking cpufreq_freq_transition_begin() and cpufreq_freq_transition_end() for those cpufreq drivers that define the ->target_index callback but don't set the ASYNC_NOTIFICATION flag. The powernow-k7 cpufreq driver falls under this category, but this driver was invoking the _begin() and _end() APIs itself around frequency transitions, which led to double invocation of the _begin() API. The _begin API makes contending callers wait until the previous invocation is complete. Hence, the powernow-k7 driver ended up waiting on itself, leading to system hangs during boot. Fix this by removing the calls to the _begin() and _end() APIs from the powernow-k7 driver, since they rightly belong to the cpufreq core. Signed-off-by: Srivatsa S. Bhat Acked-by: Viresh Kumar --- drivers/cpufreq/powernow-k7.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/cpufreq/powernow-k7.c b/drivers/cpufreq/powernow-k7.c index f911645..e61e224 100644 --- a/drivers/cpufreq/powernow-k7.c +++ b/drivers/cpufreq/powernow-k7.c @@ -269,8 +269,6 @@ static int powernow_target(struct cpufreq_policy *policy, unsigned int index) freqs.new = powernow_table[index].frequency; - cpufreq_freq_transition_begin(policy, &freqs); - /* Now do the magic poking into the MSRs. */ if (have_a0 == 1) /* A0 errata 5 */ @@ -290,8 +288,6 @@ static int powernow_target(struct cpufreq_policy *policy, unsigned int index) if (have_a0 == 1) local_irq_enable(); - cpufreq_freq_transition_end(policy, &freqs, 0); - return 0; } -- 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/