From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752904Ab3KHFYI (ORCPT ); Fri, 8 Nov 2013 00:24:08 -0500 Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:8988 "EHLO mx0a-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750986Ab3KHFYE (ORCPT ); Fri, 8 Nov 2013 00:24:04 -0500 From: Xiaoguang Chen To: , , , , CC: , Subject: [PATCH 1/2] cpufreq: conservative: fix requested_freq reduction issue Date: Fri, 8 Nov 2013 13:23:51 +0800 Message-ID: <1383888232-27049-1-git-send-email-chenxg@marvell.com> X-Mailer: git-send-email 1.8.0 MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.10.8794,1.0.431,0.0.0000 definitions=2013-11-07_08:2013-11-08,2013-11-07,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1305240000 definitions=main-1311070277 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When decreasing frequency, requested_freq may be less than freq_target, So requested_freq minus freq_target may be negative, But reqested_freq's unit is unsigned int, then the negative result will be one larger integer which may be even higher than requested_freq. This patch is to fix such issue. when result becomes negative, set requested_freq as the min value of policy. Signed-off-by: Xiaoguang Chen Acked-by: Viresh Kumar --- drivers/cpufreq/cpufreq_conservative.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index f62d822..218460f 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -80,13 +80,18 @@ static void cs_check_cpu(int cpu, unsigned int load) /* Check for frequency decrease */ if (load < cs_tuners->down_threshold) { + unsigned int freq_target; /* * if we cannot reduce the frequency anymore, break out early */ if (policy->cur == policy->min) return; - dbs_info->requested_freq -= get_freq_target(cs_tuners, policy); + freq_target = get_freq_target(cs_tuners, policy); + if (dbs_info->requested_freq > freq_target) + dbs_info->requested_freq -= freq_target; + else + dbs_info->requested_freq = policy->min; __cpufreq_driver_target(policy, dbs_info->requested_freq, CPUFREQ_RELATION_L); -- 1.8.0