On Thu, Nov 3, 2016 at 4:03 PM, hl <hl at rock-chips.com> wrote: > Hi MyungJoo Ham, > > > On 2016?11?02? 14:35, MyungJoo Ham wrote: >>> >>> Add suspend frequency support and if needed set it to >>> the frequency obtained from the suspend opp (can be defined >>> using opp-v2 bindings and is optional). >>> >>> Change-Id: Iaa0d3848d63d9ce03f65ea76f263e4685a4c295e >>> Signed-off-by: Lin Huang <hl at rock-chips.com> >>> --- >>> drivers/devfreq/devfreq.c | 17 ++++++++++++++++- >>> include/linux/devfreq.h | 9 +++++++++ >>> 2 files changed, 25 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index bf3ea76..d1152eb 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -364,7 +364,10 @@ void devfreq_monitor_suspend(struct devfreq >>> *devfreq) >>> return; >>> } >>> - devfreq_update_status(devfreq, devfreq->previous_freq); >>> + if (devfreq->suspend_freq) >>> + devfreq_update_status(devfreq, devfreq->suspend_freq); >>> + else >>> + devfreq_update_status(devfreq, devfreq->previous_freq); >> >> This is incorrect. >> >> devfreq_update_status is to record the statistics. >> This code intends to record the current status before entering suspend; >> thus you should not record "suspend_freq" here. >> >> If you really need to record the frequency during suspended state >> for the statistics, you need to do that at resume; however, I object to >> that idea either. >> >> If you really want to set a predefined suspend-to-RAM mode frequency, >> (probably because of HW instability during resume process) >> you need to update, not udpate_status (statistics). >> > Thanks for pointing it, but if i use update_devfreq(), it can not specify > the > frequency, it call the get_target_freq() to get the frequency and setting, > use now devfreq framework, it seems hard to set the specific freqeuency > when suspend. Do you have any idea, thanks. It appears that we need to set the frequency directly with target() function at suspend/resume after it is assured that related routines are already suspended. Plus, you might need to consider using devfreq_suspend/resume_device instead of monitor. monitor functions are for the governor-specific behaviors. You'll need such capabilities regardless of governors. (even userspace-governor needs this) Cheers, MyungJoo > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pm" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- MyungJoo Ham, Ph.D. Frontier CS Lab, S/W Center, Samsung Electronics
