Re: [PATCH] devfreq: simple_ondemand: Update devfreq stats when governor started

[jeffy]

Hi Ham,

oops, sorry, it turns out the devfreq would already tried to handle this 
case(by using profile's initial_freq):

8d39fc0 PM / devfreq: fix initialization of current frequency in last status

and my local kernel didn't contains this commit.

so this patch is not needed, please ignore it.

On 07/18/2017 07:27 PM, jeffy wrote:
> hi Ham,
>
> Thanks for your reply.
>
> On 07/18/2017 06:35 PM, MyungJoo Ham wrote:
> > > If governor suspends soon after started, it may not have the chance to
> > > update devfreq stats, which leaves devfreq stats' current frequence be
> > > zero.
> > >
> > > So when the thermal core tries to throttle the power, it would failed
> > > to get the correct static power of current frequence and print these
> > > warnings:
> > > [    2.024735] core: dev_pm_opp_get_voltage: Invalid parameters
> > > [    2.024743] mali ff9a0000.gpu: Failed to get voltage for frequency 0:
> > > -34
> > > ...
> > > [    2.026320] core: dev_pm_opp_get_voltage: Invalid parameters
> > > [    2.026327] mali ff9a0000.gpu: Failed to get voltage for frequency 0:
> > > -34
> > >
> > > Update devfreq stats when governor started to avoid that.
> > >
> > > Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> >
> > How are you calling suspend/resume routins in the mali drivers?
> i was porting mali driver from here:
> https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4/drivers/gpu/arm/midgard/mali_kbase_core_linux.c#4079
>
> > It appears that your mali device driver's suspend/resume routines are
> > accessing "struct devfreq_dev_status" directly. Is this correct?
> no, but the suspend/resume would suspend/resume the governor.
> > Plus, for MALI (if that assumption is correct), this issue might occur
> > with other governors.
> >
> > If so, would it be better to put the first initializing call of
> > devfreq_update_stats() at devfreq_add_device()?
> right, that make sense. i put it here because the comment of this
> function said it should be called by governor, but you're right, it
> would be better this way, will send new version soon.
> > Cheers,
> > MyungJoo
> >
> > ps. Where can I look at the mali-devfreq device driver? (I couldn't
> > find it)
> sorry, i should mention that, please check above link :)
> >