Re: [PATCH 2/2] drm/panfrost: add devfreq regulator support

[Robin Murphy]

On 2020-04-13 3:18 pm, ClÃment PÃron wrote:
> Hi Steven,
>
> On Mon, 13 Apr 2020 at 15:18, Steven Price <steven.price@xxxxxxx> wrote:
> > On 11/04/2020 21:06, ClÃment PÃron wrote:
> > > OPP table can defined both frequency and voltage.
> > >
> > > Register the mali regulator if it exist.
> > >
> > > Signed-off-by: ClÃment PÃron <peron.clem@xxxxxxxxx>
> > > ---
> > >    drivers/gpu/drm/panfrost/panfrost_devfreq.c | 34 ++++++++++++++++++---
> > >    drivers/gpu/drm/panfrost/panfrost_device.h  |  1 +
> > >    2 files changed, 31 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > > index 62541f4edd81..2dc8e2355358 100644
> > > --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > > +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > > @@ -78,12 +78,26 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
> > >        struct device *dev = &pfdev->pdev->dev;
> > >        struct devfreq *devfreq;
> > >        struct thermal_cooling_device *cooling;
> > > +     const char *mali = "mali";
> > > +     struct opp_table *opp_table = NULL;
> > > +
> > > +     /* Regulator is optional */
> > > +     opp_table = dev_pm_opp_set_regulators(dev, &mali, 1);
> >
> > This looks like it applies before 3e1399bccf51 ("drm/panfrost: Add
> > support for multiple regulators") which is currently in drm-misc-next
> > (and linux-next). You want something more like:
>
> Thanks for you review, indeed I didn't see that multiple regulators
> support has been added.
> Will update in v2.

Although note that we probably also want a version that can be 
backported to stable without that dependency, since this behaviour is 
arguably a regression since 221bc77914cb ("drm/panfrost: Use generic 
code for devfreq"), and does appear to have been causing subtle problems 
for users.

Robin.