From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752148AbdJLEIK (ORCPT ); Thu, 12 Oct 2017 00:08:10 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:45529 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750722AbdJLEII (ORCPT ); Thu, 12 Oct 2017 00:08:08 -0400 X-AuditID: b6c32a35-8adff70000001157-0c-59deeaa57f9d MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset="utf-8" Message-id: <59DEEAA5.3050905@samsung.com> Date: Thu, 12 Oct 2017 13:08:05 +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: cwchoi00@gmail.com, "myungjoo.ham@samsung.com" Cc: Kyungmin Park , "rafael.j.wysocki@intel.com" , Inki Dae , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" Subject: Re: [PATCH v3 3/8] PM / devfreq: Show the available min/max frequency through sysfs node In-reply-to: X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrGKsWRmVeSWpSXmKPExsWy7bCmvu7SV/ciDfbc4Ld4dlTbYtL9CSwW Z5vesFtc3jWHzeJz7xFGi9uNK9gsHq94y+7A7rFz1l12j8V7XjJ59G1ZxejxeZNcAEtUqk1G amJKapFCal5yfkpmXrqtkndwvHO8qZmBoa6hpYW5kkJeYm6qrZKLT4CuW2YO0AFKCmWJOaVA oYDE4mIlfTubovzSklSFjPziElulaENDIz1DA3M9IyMjPRPjWCsjU6CShNSM9glnmQveSFYs eXyVrYFxs0gXIyeHhICJxMG1W9hBbCGBHYwSUzdYdjFyAdnfGSVeX3zOAlPUsP0wG0RiN6PE uc5JYB28AoISPybfAyri4GAWkJc4cikbJMwsoCnx4sskFoj6e4wSS6b+ZoKo15K49n0uK4jN IqAq8XbxVjYQmw0ovv/FDTCbX0BR4uqPx4wgtqhAhMTO+d/AdokI+Et87H/ICjKUWaCVSaJx /kmwhLBAssSktu9gl3IKBEvM6W0Eu1RC4AibxLJ/E9kgXnCROPHgIpQtLPHqOMjPHEC2tMSl o7YQ9e2MEpvn3GOBcDoYJe6vbGSFaDCWONXVyATxG5/Eu689rBDNvBIdbUIQJR4SM7fMhgaX o0TrsmVQ719ikji18jzTBEa5WUghNgsRYrOQQmwBI/MqRrHUguLc9NRiwwJDveLE3OLSvHS9 5PzcTYzgNKdluoNxyjmfQ4wCHIxKPLwTNO5FCrEmlhVX5h5ilOBgVhLh9d8FFOJNSaysSi3K jy8qzUktPsRoCgzwicxSosn5wBScVxJvaGJpYGJmBExfloaGSuK8ouuvRQgJpCeWpGanphak FsH0MXFwSjUw+j+2ddVcXNPQubR97/Jy6ZWXIlVV9uz6vzJznxhLjNw1pq3/PqqptcjOO/+r RD09VSBmgl3ZDvfJptc6ZK+5iN0Wfnqv0GKLbezGeTc3znerlLH7s+3PcdMdrkejGS/vk2d7 8sTi0uU/1QzHvVitlSa9z3NIq5/KcXT+NL3sbw/2SV38+PWmhBJLcUaioRZzUXEiAFXW5N2J AwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrGLMWRmVeSWpSXmKPExsVy+t9jAd2lr+5FGsyewWjx7Ki2xaT7E1gs zja9Ybe4vGsOm8Xn3iOMFrcbV7BZPF7xlt2B3WPnrLvsHov3vGTy6NuyitHj8ya5AJYoLpuU 1JzMstQifbsEroz2CWeZC95IVix5fJWtgXGzSBcjJ4eEgIlEw/bDbF2MXBxCAjsZJR70XGEC SfAKCEr8mHyPpYuRg4NZQF7iyKVsCFNdYsqUXIjyB4wSs74fYIQo15K49n0uK4jNIqAq8Xbx VjYQmw0ovv/FDTCbX0BR4uqPx4wgc0QFIiS6T1SChEUEfCUW7bzPDDKTWaCdSeLx5G6wOcIC yRJzvlxhhVh2iUnizM2T7CDNnALBEp/esk5gFJiF5NJZCJfOQrh0ASPzKkbJ1ILi3PTcYqMC w7zUcr3ixNzi0rx0veT83E2MwNDedlirbwfj/SXxhxgFOBiVeHhfaN2LFGJNLCuuzD3EKMHB rCTC678LKMSbklhZlVqUH19UmpNafIhRmoNFSZz3dt6xSCGB9MSS1OzU1ILUIpgsEwenVANj jUxY+vs5H9VePm+ttH/lHqB8/07Ci7fmz65G1gYVBXhP3t83+01LVv7FGcna22MsnlXNOLfj 59KGhB0nD5c//vFo562mqM2MIr7+AnlT3m+89OHaIZsF9QI26/vOCmioTC6RLd/1+s8KVpaz j0VX/NqcKD1tq+u72esZX0b4P3jzqCtqf6/ITCWW4oxEQy3mouJEAMpR+WppAgAA X-CMS-MailID: 20171012040805epcas1p10dc11cc441918d98c8b905d3d969993e X-Msg-Generator: CA X-Sender-IP: 182.195.42.142 X-Local-Sender: =?UTF-8?B?7LWc7LCs7JqwG1RpemVuIFBsYXRmb3JtIExhYihTL1fshLw=?= =?UTF-8?B?7YSwKRvsgrzshLHsoITsnpAbU2VuaW9yIEVuZ2luZWVy?= X-Global-Sender: =?UTF-8?B?Q2hhbndvbyBDaG9pG1RpemVuIFBsYXRmb3JtIExhYi4bU2Ft?= =?UTF-8?B?c3VuZyBFbGVjdHJvbmljcxtTZW5pb3IgRW5naW5lZXI=?= X-Sender-Code: =?UTF-8?B?QzEwG1RFTEUbQzEwVjgxMTE=?= CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20171011030946epcas1p40f32955da5dada46e95302701a0afb7d X-RootMTR: 20171011030946epcas1p40f32955da5dada46e95302701a0afb7d References: <1507691364-3899-1-git-send-email-cw00.choi@samsung.com> <1507691364-3899-4-git-send-email-cw00.choi@samsung.com> <20171011111532epcms1p3036bcc7be2cc00057fe478fc868ba71d@epcms1p3> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017년 10월 11일 21:57, Chanwoo Choi wrote: > On Wed, Oct 11, 2017 at 8:15 PM, MyungJoo Ham wrote: >>> The existing {min|max}_freq sysfs nodes don't consider whether min/max_freq >>> are available or not. Those sysfs nodes show just the stored value >>> in the struct devfreq. >>> >>> The devfreq uses the OPP interface and then dev_pm_opp_{disable|add}() >>> might change the state of the device's supported frequency. This patch >>> shows the available minimum and maximum frequency through sysfs node. >>> >>> Signed-off-by: Chanwoo Choi >>> --- >>> drivers/devfreq/devfreq.c | 18 ++++++++++++++++-- >>> 1 file changed, 16 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index 2ce1fd0a1324..799a0cf75d39 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -1128,7 +1128,14 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, >>> static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, >>> char *buf) >>> { >>> - return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); >>> + struct devfreq *df = to_devfreq(dev); >>> + unsigned long min_freq = to_devfreq(dev)->min_freq; >>> + unsigned long available_min_freq = find_available_min_freq(df); >>> + >>> + if (available_min_freq != 0 && min_freq < available_min_freq) >> >> nitpick: >> >> If available_min_freq == 0, >> it can't be min_freq < available_min_freq anyway; >> it's unsigned. > > If the dev_pm_opp_find_*() return the error in the find_available_min_freq(), > avaiable_min_freq is zero. So, if available_min_freq is zero, > min_freq_show doesn't need to compare 'min_freq < available_min_freq'. > > In result, if 'available_min_freq' is zero, min_freq_show() only considers > the 'min_freq' variable. I'll modify this patch as following: How about that? + if (available_min_freq == 0) + goto out; + else if (min_freq < available_min_freq) + min_freq = available_min_freq; + +out: + return sprintf(buf, "%lu\n", min_freq); >> >>> + min_freq = available_min_freq; >>> + >>> + return sprintf(buf, "%lu\n", min_freq); >>> } >>> >>> static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, >>> @@ -1162,7 +1169,14 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, >>> static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, >>> char *buf) >>> { >>> - return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); >>> + struct devfreq *df = to_devfreq(dev); >>> + unsigned long max_freq = to_devfreq(dev)->max_freq; >>> + unsigned long available_max_freq = find_available_max_freq(df); >>> + >>> + if (available_max_freq != 0 && max_freq > available_max_freq) >>> + max_freq = available_max_freq; >> >> similar here. > > ditto. > >> >>> + >>> + return sprintf(buf, "%lu\n", max_freq); >>> } >>> static DEVICE_ATTR_RW(max_freq); > > -- Best Regards, Chanwoo Choi Samsung Electronics