From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754468AbcJZHWz (ORCPT ); Wed, 26 Oct 2016 03:22:55 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:48807 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751792AbcJZHWv (ORCPT ); Wed, 26 Oct 2016 03:22:51 -0400 MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 X-AuditID: cbfee61a-f79926d000005981-32-581059c9132e Content-transfer-encoding: 8BIT Message-id: <581059C8.3000408@samsung.com> Date: Wed, 26 Oct 2016 16:22:48 +0900 From: Chanwoo Choi Organization: Samsung Electronics User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: Saravana Kannan , "Rafael J. Wysocki" , MyungJoo Ham , Kyungmin Park , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] PM / devfreq: Restart previous governor if new governor fails to start References: <1477445160-990-1-git-send-email-skannan@codeaurora.org> In-reply-to: <1477445160-990-1-git-send-email-skannan@codeaurora.org> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrJIsWRmVeSWpSXmKPExsVy+t9jQd2TkQIRBo2P+SzONr1ht7i8aw6b xefeI4wWtxtXsFmcOX2J1eLAxYlsDmwel/t6mTy2XG1n8ejbsorR4/MmuQCWKDebjNTElNQi hdS85PyUzLx0W6XQEDddCyWFvMTcVFulCF3fkCAlhbLEnFIgz8gADTg4B7gHK+nbJbhl7Gie xl4wn7/iTF8rSwPjBp4uRk4OCQETieULv7NA2GISF+6tZ+ti5OIQEpjFKHHl+wVGkASvgKDE j8n3gIo4OJgF5CWOXMoGCTMLqEtMmreIGaL+AaNEx5ImNpAaXgEtiVcH0kBqWARUJf517WMD sdmAwvtf3ACz+QUUJa7+eMwIUi4qECHRfaISZIyIwEtGiYc3u1lBaoQFEiQ29YOshbpn975P YPdwCrhK3Hsxn3ECI1AU4bxZCOfNQnLeAkbmVYwSqQXJBcVJ6bmGeanlesWJucWleel6yfm5 mxjB0fRMagfjwV3uhxgFOBiVeHgrjvJHCLEmlhVX5h5ilOBgVhLhtQgRiBDiTUmsrEotyo8v Ks1JLT7EaAr04ERmKdHkfGCk55XEG5qYm5gbG1iYW1qaGCmJ8zbOfhYuJJCeWJKanZpakFoE 08fEwSnVwBi+pvZrzPPquYGiMy3eb/69qnKNsu3jZXPXq1ellTB13ZX/tGxT7DRBA970uT3c efwf9kvc/Ts7aU11gsPauzJczQwLWT3CgiREtZS1o5eIGzN/rZM+uzP3jbf/KYe0O2aNu4u8 hTgvsLfp1wVfFEz7nMDI8WkPc+fsLQesrrdwlIYqKuc2K7EUZyQaajEXFScCAPLuM6K8AgAA X-MTR: 20000000000000000@CPGS Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2016년 10월 26일 10:25, Saravana Kannan wrote: > If the new governor fails to start, switch back to old governor so that the > devfreq state is not left in some weird limbo. > > Signed-off-by: Saravana Kannan > --- > * Fixed typo in commit text > * Fixed potential NULL deref > > drivers/devfreq/devfreq.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index bf3ea76..243253e 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -919,7 +919,7 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr, > struct devfreq *df = to_devfreq(dev); > int ret; > char str_governor[DEVFREQ_NAME_LEN + 1]; > - struct devfreq_governor *governor; > + const struct devfreq_governor *governor, *prev_gov; > > ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); > if (ret != 1) > @@ -944,12 +944,17 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr, > goto out; > } > } > + prev_gov = df->governor; > df->governor = governor; > strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); > ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); > - if (ret) > + if (ret) { > dev_warn(dev, "%s: Governor %s not started(%d)\n", > __func__, df->governor->name, ret); > + df->governor = prev_gov; > + strncpy(df->governor_name, prev_gov->name, DEVFREQ_NAME_LEN); > + df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); > + } > out: > mutex_unlock(&devfreq_list_lock); > > Looks good to me. But, how about using the 'prev_governor' instead of 'prev_gov'? because the variable name of current governor is 'governor' instead of 'gov'. Reviewed-by: Chanwoo Choi -- Best Regards, Chanwoo Choi