From patchwork Fri Apr 25 08:18:35 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Srivatsa S. 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Violators will be prosecuted for from ; Fri, 25 Apr 2014 13:49:19 +0530 Received: from d28dlp01.in.ibm.com (9.184.220.126) by e28smtp09.in.ibm.com (192.168.1.139) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Fri, 25 Apr 2014 13:49:16 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id CBB0CE0056; Fri, 25 Apr 2014 13:53:43 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s3P8J8Y57340518; Fri, 25 Apr 2014 13:49:08 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s3P8JFFA004775; Fri, 25 Apr 2014 13:49:15 +0530 Received: from srivatsabhat.in.ibm.com ([9.77.200.213]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s3P8JESS004734; Fri, 25 Apr 2014 13:49:14 +0530 From: "Srivatsa S. Bhat" Subject: [PATCH 3/3] 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: Fri, 25 Apr 2014 13:48:35 +0530 Message-ID: <20140425081830.10258.10979.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20140425081728.10258.63980.stgit@srivatsabhat.in.ibm.com> References: <20140425081728.10258.63980.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14042508-2674-0000-0000-00000DF56D28 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- drivers/cpufreq/powernow-k7.c | 4 ---- 1 file changed, 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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; }