On Tue, Feb 22, 2022 at 2:10 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> On Thu, Feb 17, 2022 at 2:42 PM Brian Norris <briannorris@xxxxxxxxxxxx> wrote:
> > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> > @@ -1121,7 +1121,7 @@ static int analogix_dp_get_modes(struct drm_connector *connector)
> >
> > pm_runtime_get_sync(dp->dev);
> > edid = drm_get_edid(connector, &dp->aux.ddc);
> > - pm_runtime_put(dp->dev);
> > + pm_runtime_put_autosuspend(dp->dev);
>
> So I think you can fully get rid of these ones now and rely on the
> ones in the aux transfer, right?
Yep, good catch.
> > if (edid) {
> > drm_connector_update_edid_property(&dp->connector,
> > edid);
> > @@ -1642,7 +1642,7 @@ static ssize_t analogix_dpaux_transfer(struct drm_dp_aux *aux,
> >
> > ret = analogix_dp_transfer(dp, msg);
> > out:
> > - pm_runtime_put(dp->dev);
> > + pm_runtime_put_autosuspend(dp->dev);
> >
> > return ret;
> > }
> > @@ -1775,6 +1775,8 @@ int analogix_dp_bind(struct analogix_dp_device *dp, struct drm_device *drm_dev)
> > if (ret)
> > return ret;
> >
> > + pm_runtime_use_autosuspend(dp->dev);
> > + pm_runtime_set_autosuspend_delay(dp->dev, 100);
>
> It's explicitly listed in the Documentation that you need the
> corresponding pm_runtime_dont_use_autosuspend(). Specifically, it
> says:
>
> > Drivers in ->remove() callback should undo the runtime PM changes done
> > in ->probe(). Usually this means calling pm_runtime_disable(),
> > pm_runtime_dont_use_autosuspend() etc.
>
> Not that it's very common to see anyone actually get it right, but I
> seem to remember running into an issue when I didn't do it. I think
> ti-sn65dsi86 still has it wrong since I found out about this later.
> Need to write a patch up for that... Basically you want to put it
> right before the two calls in your driver to pm_runtime_disable().
Ack.
Speaking of API misfeatures that we missed: I've failed to call
pm_runtime_mark_last_busy(). I'll add that in the next rev, for the
cases where we weren't already calling *_put_sync() (i.e., presumably
we don't really care to wait around for autosuspend).
*gripe* What a silly API. *gripe*
Brian
