From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752095AbeEQX0p (ORCPT ); Thu, 17 May 2018 19:26:45 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:46722 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbeEQX0l (ORCPT ); Thu, 17 May 2018 19:26:41 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20180517232639epoutp016e8ccbbb07b92f8c614e8f0f7889c115~vkj9mzW1W2841228412epoutp013 X-AuditID: b6c32a35-9e3ff70000001024-4f-5afe0fa7cd86 MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset="utf-8" Message-id: <5AFE0FA6.4020101@samsung.com> Date: Fri, 18 May 2018 08:26:30 +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: Matthias Kaehlcke Cc: MyungJoo Ham , Kyungmin Park , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Brian Norris Subject: Re: [RFC PATCH] PM / devfreq: Add policy notifier In-reply-to: <20180517230728.GQ19594@google.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrLKsWRmVeSWpSXmKPExsWy7bCmnu5y/n9RBnevKVts+vie1eJs0xt2 i8u75rBZfO49wmjxecNjRovbjSvYHNg8ZjdcZPHo27KK0ePzJrkA5qhUm4zUxJTUIoXUvOT8 lMy8dFsl7+B453hTMwNDXUNLC3MlhbzE3FRbJRefAF23zBygvUoKZYk5pUChgMTiYiV9O5ui /NKSVIWM/OISW6VoQ0MjPUMDcz0jIyBtHGtlZApUkpCa8efLB6aC3XwVjz+cYmxgvMzdxcjJ ISFgInH7xFMmEFtIYAejxMqWrC5GLiD7O6PEk+uvmGCKvkzcwAyR2M0oce7ODDaQBK+AoMSP yfdYuhg5OJgF5CWOXMoGCTMLaEq8+DKJBaL+LqNE0/8Z7BD1WhIHnu4G62URUJW4NaGLEcRm A4rvf3EDLM4voChx9cdjsLioQITEzvnfwHpFBDQknvw+zwgylBnkiKU7/oEVCQtYSdyYt44V xOYUMJD4OOk2O0iRhMAONonZ/w6wQLzgIjH91HZ2CFtY4tXxLewgV0sISEtcOmoLUd/OKNG+ dx4zhDMF6M3r96D+N5Z4trCLCeI3Pol3X3tYIZp5JTrahCBKPCT+3p/ICmE7Snz5dpAR4v2z jBJP37cyT2CUm4UUYrMQITYLKcQWMDKvYhRLLSjOTU8tNiww1CtOzC0uzUvXS87P3cQITmpa pjsYp5zzOcQowMGoxMM7of9vlBBrYllxZe4hRgkOZiURXr9KoBBvSmJlVWpRfnxRaU5q8SFG U2CAT2SWEk3OBybcvJJ4Q1MjY2NjCxNDM1NDQyVx3jlKX6OEBNITS1KzU1MLUotg+pg4OKUa GA1qjCWFkyc3Pfi9327Zl7wTJZJpCU7z16+9xSchdmVX1Kqakp9PLI7b3ymwuajE0vydIUIi /nxZU8A1rud8M0/GHnCe3sK6rv2S0pw3wh0ZSsvdCvJ73+iY7opc7Me+YYn8brYp0abc/1Nf /z/ocODZo7+b4vKffU54aHnn4MyAIBuz/UyKtUosxRmJhlrMRcWJAJI2nMiAAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrNLMWRmVeSWpSXmKPExsVy+t9jAd3l/P+iDB4fZLHY9PE9q8XZpjfs Fpd3zWGz+Nx7hNHi84bHjBa3G1ewObB5zG64yOLRt2UVo8fnTXIBzFFcNimpOZllqUX6dglc GX++fGAq2M1X8fjDKcYGxsvcXYycHBICJhJfJm5g7mLk4hAS2MkoMXvCGnaQBK+AoMSPyfdY uhg5OJgF5CWOXMqGMNUlpkzJBakQErjPKPHwjRVEtZbEgae72UBsFgFViVsTuhhBbDag+P4X N8Di/AKKEld/PGYEGSMqECHRfaISJCwioCHx5Pd5sHJmgd2MEmtWaIPYwgJWEjfmrWOFWHWe UWJHkzeIzSlgIPFx0m32CYwCs5DcOQvhzlkIdy5gZF7FKJlaUJybnltsVGCYl1quV5yYW1ya l66XnJ+7iREYxNsOa/XtYLy/JP4QowAHoxIP74uJf6OEWBPLiitzDzFKcDArifD6VQKFeFMS K6tSi/Lji0pzUosPMUpzsCiJ897OOxYpJJCeWJKanZpakFoEk2Xi4JRqYOyXZ3kcsD117cyp n2cdShd5ZjN9dsBu04a0H7PuLF543OWM5t/L61jOL9V4pcxY9C47QcY2mi120yzWfKFHGaGz PPKfvj4SUV4246DhJJNOkXfzDEIEHCTWHuPr7e9NX+UrLjvXxe8PS/TfT4vTygVVhHknzr2V J5i+XP2i7WPGwl888xJufVJiKc5INNRiLipOBACGzV2JXgIAAA== X-CMS-MailID: 20180517232631epcas1p405e6b7ea3590cc51ef35ea77e0930624 X-Msg-Generator: CA CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20180515212545epcas1p2bdfd9c90f2ce6b74ac0fdd8cd9f9f63b X-RootMTR: 20180515212545epcas1p2bdfd9c90f2ce6b74ac0fdd8cd9f9f63b References: <20180515212447.180595-1-mka@chromium.org> <5AFCE27E.20803@samsung.com> <20180517230728.GQ19594@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2018년 05월 18일 08:07, Matthias Kaehlcke wrote: > Hi, > > On Thu, May 17, 2018 at 11:01:34AM +0900, Chanwoo Choi wrote: >> Hi, >> >> Could you give some use-case of DEVFREQ_POLICY_NOTIFIER >> or send use-case patch with this patch? > > This is a WIP patch that makes use of the DEVFREQ_POLICY_NOTIFIER: > > https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1065122 > >> I already knew the CPUFREQ_POLICY_NOTIFIER. >> But, until now, there are no any requirements of DEVFREQ_POLICY_NOTIFIER. >> If there are no any use-case, it is not necessary codes. > > Sure, I intend to land the above driver upstream if devfreq can > provide the necessary interfaces. I recommend that you should send the patch with the use-case patch. > >> On 2018년 05월 16일 06:24, Matthias Kaehlcke wrote: >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index fe2af6aa88fc..a7294c056f65 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -273,6 +273,9 @@ int update_devfreq(struct devfreq *devfreq) >>> if (err) >>> return err; >>> >>> + srcu_notifier_call_chain(&devfreq->policy_notifier_list, >>> + DEVFREQ_ADJUST, &freq); >> >> It is not proper to used 'freq' as the passed data. >> In current step,'freq' is not adjusted and is not final decided >> frequency. > > Right, the next revision will pass a struct devfreq_policy instead, > where the notifiers can adjust the min/max values, similar to what > cpufreq does. Actually, I don't know the devfreq_policy(?). As I already commented, it is not proper to discuss it because there is no any real code and patches. It is difficult to understand for me. > > Thanks > > Matthias > > > -- Best Regards, Chanwoo Choi Samsung Electronics