From mboxrd@z Thu Jan 1 00:00:00 1970 From: cw00.choi@samsung.com (Chanwoo Choi) Date: Thu, 22 Nov 2018 11:54:50 +0900 Subject: [PATCH 2/6] devfreq: refactor set_target frequency function In-Reply-To: <5BF619EE.8090006@samsung.com> References: <1542823301-23563-1-git-send-email-l.luba@partner.samsung.com> <1542823301-23563-3-git-send-email-l.luba@partner.samsung.com> <5BF619EE.8090006@samsung.com> Message-ID: <5BF61A7A.1060805@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2018? 11? 22? 11:52, Chanwoo Choi wrote: > On 2018? 11? 22? 03:01, Lukasz Luba wrote: >> The refactoring is needed for the new client in devfreq: suspend. >> To avoid code duplication, move it to the new local function >> devfreq_set_target. >> >> The patch draws on Tobias Jakobi's work posted ~2 years ago, who tried to >> solve issue with devfreq device's frequency during suspend/resume. >> During the discussion on LKML some corner cases and comments appeared >> related to the design. This patch address them keeping in mind suggestions >> from Chanwoo Choi. > > As I commented on patch1, please remove it. > >> >> Suggested-by: Tobias Jakobi >> Suggested-by: Chanwoo Choi >> Signed-off-by: Lukasz Luba >> --- >> drivers/devfreq/devfreq.c | 62 ++++++++++++++++++++++++++++------------------- >> 1 file changed, 37 insertions(+), 25 deletions(-) >> >> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >> index e20e7e4..cf9c643 100644 >> --- a/drivers/devfreq/devfreq.c >> +++ b/drivers/devfreq/devfreq.c >> @@ -285,6 +285,42 @@ static int devfreq_notify_transition(struct devfreq *devfreq, >> return 0; >> } >> >> +static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq, >> + unsigned long *prev_freq, u32 flags) > > Please remove the unused space in front of 'unsigned long *prev_freq'. > Use tab only for indentation. > >> +{ >> + struct devfreq_freqs freqs; >> + unsigned long cur_freq; >> + int err = 0; >> + >> + if (devfreq->profile->get_cur_freq) >> + devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq); >> + else >> + cur_freq = devfreq->previous_freq; >> + >> + freqs.old = cur_freq; >> + freqs.new = new_freq; >> + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE); >> + >> + err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags); >> + if (err) { >> + freqs.new = cur_freq; >> + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >> + return err; >> + } >> + >> + freqs.new = new_freq; >> + devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >> + >> + if (devfreq_update_status(devfreq, new_freq)) >> + dev_err(&devfreq->dev, >> + "Couldn't update frequency transition information.\n"); >> + >> + devfreq->previous_freq = new_freq; >> + *prev_freq = cur_freq; >> + >> + return err; >> +} You can change the devfreq_set_target as following: static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq, - unsigned long *prev_freq, u32 flags) + u32 flags) { struct devfreq_freqs freqs; unsigned long cur_freq; @@ -319,7 +319,9 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq, "Couldn't update frequency transition information.\n"); devfreq->previous_freq = new_freq; - *prev_freq = cur_freq; But, you have to add following new code on patch3 instead of patch2. + + if (devfreq->suspend_freq) + devfreq->resume_freq = cur_freq; return err; } >> + >> /* Load monitoring helper functions for governors use */ >> >> /** >> @@ -296,7 +332,6 @@ static int devfreq_notify_transition(struct devfreq *devfreq, >> */ >> int update_devfreq(struct devfreq *devfreq) >> { >> - struct devfreq_freqs freqs; >> unsigned long freq, cur_freq, min_freq, max_freq; > > > cur_freq is not used after modification. Remove it. > >> int err = 0; >> u32 flags = 0; >> @@ -333,31 +368,8 @@ int update_devfreq(struct devfreq *devfreq) >> flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ >> } >> >> - if (devfreq->profile->get_cur_freq) >> - devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq); >> - else >> - cur_freq = devfreq->previous_freq; >> - >> - freqs.old = cur_freq; >> - freqs.new = freq; >> - devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE); >> + return devfreq_set_target(devfreq, freq, &cur_freq, flags); > > You get the 'cur_freq' from devfreq_set_taget() for devfreq_suspend_device() on patch3. > But, update_devfreq() and devfreq_resume_device() don't use the 'cur_freq' value > from devfreq_set_target(). > > Instead, getting 'cur_freq' for 'devfreq->resume_freq' in the devfreq_set_target(). > Please remove the 'cur_freq' parameter from devfreq_set_target. > >> >> - err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); >> - if (err) { >> - freqs.new = cur_freq; >> - devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >> - return err; >> - } >> - >> - freqs.new = freq; >> - devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); >> - >> - if (devfreq_update_status(devfreq, freq)) >> - dev_err(&devfreq->dev, >> - "Couldn't update frequency transition information.\n"); >> - >> - devfreq->previous_freq = freq; >> - return err; >> } >> EXPORT_SYMBOL(update_devfreq); >> >> > > -- Best Regards, Chanwoo Choi Samsung Electronics