From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756939Ab2IJJ2E (ORCPT ); Mon, 10 Sep 2012 05:28:04 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:63214 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756645Ab2IJJ17 (ORCPT ); Mon, 10 Sep 2012 05:27:59 -0400 X-AuditID: cbfee612-b7f5c6d0000048e4-71-504db29c2b4a Date: Mon, 10 Sep 2012 09:27:56 +0000 (GMT) From: MyungJoo Ham Subject: Re: [PATCH 2/3] devfreq: Add suspend and resume apis To: Rajagopal Venkat , "mturquette@linaro.org" , =?euc-kr?Q?=B9=DA=B0=E6=B9=CE?= , "rjw@sisk.pl" Cc: "patches@linaro.org" , "linaro-dev@lists.linaro.org" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Reply-to: myungjoo.ham@samsung.com MIME-version: 1.0 X-MTR: 20120910091659373@myungjoo.ham Msgkey: 20120910091659373@myungjoo.ham X-EPLocale: ko_KR.euc-kr X-Priority: 3 X-EPWebmail-Msg-Type: personal X-EPWebmail-Reply-Demand: 0 X-EPApproval-Locale: X-EPHeader: ML X-EPTrCode: X-EPTrName: X-MLAttribute: X-RootMTR: 20120910091659373@myungjoo.ham X-ParentMTR: X-ArchiveUser: X-CPGSPASS: N Content-type: text/plain; charset=euc-kr MIME-version: 1.0 Message-id: <23261060.329611347269273674.JavaMail.weblogic@epml28> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrNIsWRmVeSWpSXmKPExsVy+t/tmbpzNvkGGDTtNbK4vGsOmwOjx+dN cgGMUVw2Kak5mWWpRfp2CVwZR6f+YCr4YlRx7NNi1gbGE4ZdjJwcQgLqEouWnGQDsSUETCT2 3VzMCGGLSVy4tx4ozgVUM59R4lXDV9YuRg4OFgFViZ5eTRCTTUBPYubnZJByYQFbiWsrboKV iwgcZ5T4ufkDE0iCWeAZo8S57R4Qu5Qk1ux7xQJi8woISpyc+YQFYpeqxIEv3VBxNYkPG+ZB 3SAhMWv6BVYIm1diRvtTqHo5iWlf1zBD2NIS52dtgLt58ffHUHF+iWO3dzCB3AnS++R+MMyY 3Zu/QL0rIDH1zEGoVi2JGUueQtl8EmsWvmWBGbPr1HJmmN77W+ZCvaUoMaX7ITuErSXx5cc+ NnRv8Qo4SVy93806gVFuFpLULCTts5C0I6tZwMiyilE0tSC5oDgpPdVCrzgxt7g0L10vOT93 EyM4yp8J7WBc1mBxiFGAg1GJh7fTxDdAiDWxrLgy9xCjBAezkgivSB9QiDclsbIqtSg/vqg0 J7X4EKM0B4uSOO+cF1/8hQTSE0tSs1NTC1KLYLJMHJxSDYyHzq1SunKts0N+Utm2RWvf91QJ r7zH7bhL4YpP20uFn/VLkv69SM71L9uhs3r9042BLEujalbO5Y85Z+sTpO/p6MIs/l3PVjyA taVUtd2+Iz3iaMlMib3ZzP8jRMLryh08tc7dn33WdebFtcnpW5VcOu69jLlyoME9dvL1mmV1 bw6s/No0i0eJpTgj0VCLuag4EQDBtb+q7gIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id q8A9S9GW017015 > Add devfreq suspend/resume apis for devfreq users. This patch > supports suspend and resume of devfreq load monitoring, required > for devices which can idle. > > Signed-off-by: Rajagopal Venkat Rather than letting device driver be responsible to call devfreq_suspend_device() or devfreq_dev_suspend(),would there be any problems in using pm notifier here? (calling the event handler with DEVFREQ_GOV_SUSPEND/RESUME at pm notifier, stopping them earlier and resuming tham later) What devfreq-core and devfreq-governors do with suspend/resume is handling the delayed workqueue and it does not have anything to do with device-specific tasks. Thus, having each device driver handle device-specifics with its own pm_ops and having devfreq-core stop sampling seem appropriate. Putting another burden to each device driver (to call devfreq_suspend/resume_device() at its pm_ops) for an obvious task that could be done at core doesn't seem fair. Thank you. Cheers! MyungJoo > --- > drivers/devfreq/devfreq.c | 26 ++++++++++++++++++++++++++ > drivers/devfreq/governor.h | 2 ++ > drivers/devfreq/governor_simpleondemand.c | 9 +++++++++ > include/linux/devfreq.h | 12 ++++++++++++ > 4 files changed, 49 insertions(+) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index be524c7..3a5f126 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -365,6 +365,32 @@ int devfreq_remove_device(struct devfreq *devfreq) > } > EXPORT_SYMBOL(devfreq_remove_device); > > +/** > + * devfreq_suspend_device() - Suspend devfreq of a device. > + * @devfreq the devfreq instance to be suspended > + */ > +int devfreq_suspend_device(struct devfreq *devfreq) > +{ > + if (!devfreq) > + return -EINVAL; > + > + return devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_SUSPEND); > +} > +EXPORT_SYMBOL(devfreq_suspend_device); > + > +/** > + * devfreq_resume_device() - Resume devfreq of a device. > + * @devfreq the devfreq instance to be resumed > + */ > +int devfreq_resume_device(struct devfreq *devfreq) > +{ > + if (!devfreq) > + return -EINVAL; > + > + return devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_RESUME); > +} > +EXPORT_SYMBOL(devfreq_resume_device); > + > static ssize_t show_governor(struct device *dev, > struct device_attribute *attr, char *buf) > { > diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h > index 4a86af7..7dbbdfc 100644 > --- a/drivers/devfreq/governor.h > +++ b/drivers/devfreq/governor.h > @@ -22,6 +22,8 @@ > #define DEVFREQ_GOV_START 0x1 > #define DEVFREQ_GOV_STOP 0x2 > #define DEVFREQ_GOV_INTERVAL 0x3 > +#define DEVFREQ_GOV_SUSPEND 0x4 > +#define DEVFREQ_GOV_RESUME 0x5 > > /* Caution: devfreq->lock must be locked before calling update_devfreq */ > extern int update_devfreq(struct devfreq *devfreq); > diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c > index 9802bf9..35b8e8e 100644 > --- a/drivers/devfreq/governor_simpleondemand.c > +++ b/drivers/devfreq/governor_simpleondemand.c > @@ -113,6 +113,15 @@ int devfreq_simple_ondemand_handler(struct devfreq *devfreq, > else > ret = devfreq_monitor_resume(devfreq); > break; > + > + case DEVFREQ_GOV_SUSPEND: > + ret = devfreq_monitor_suspend(devfreq); > + break; > + > + case DEVFREQ_GOV_RESUME: > + ret = devfreq_monitor_resume(devfreq); > + break; > + > default: > break; > } > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h > index 7a11c3e..7c7e179 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -155,6 +155,8 @@ extern struct devfreq *devfreq_add_device(struct device *dev, > const struct devfreq_governor *governor, > void *data); > extern int devfreq_remove_device(struct devfreq *devfreq); > +extern int devfreq_suspend_device(struct devfreq *devfreq); > +extern int devfreq_resume_device(struct devfreq *devfreq); > > /* Helper functions for devfreq user device driver with OPP. */ > extern struct opp *devfreq_recommended_opp(struct device *dev, > @@ -208,6 +210,16 @@ static int devfreq_remove_device(struct devfreq *devfreq) > return 0; > } > > +static int devfreq_suspend_device(struct devfreq *devfreq) > +{ > + return 0; > +} > + > +static int devfreq_resume_device(struct devfreq *devfreq) > +{ > + return 0; > +} > + > static struct opp *devfreq_recommended_opp(struct device *dev, > unsigned long *freq, u32 flags) > { > -- > 1.7.11.3 > > > > > > > > {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I