Re: [PATCH] drm/bridge: ti-sn65dsi86: Properly undo autosuspend

From: Laurent Pinchart
Date: Wed Feb 23 2022 - 00:08:05 EST


On Tue, Feb 22, 2022 at 11:44:54PM +0100, Linus Walleij wrote:
> On Tue, Feb 22, 2022 at 11:19 PM Douglas Anderson <dianders@xxxxxxxxxxxx> wrote:
> >
> > The PM Runtime docs say:
> > 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.
> >
> > We weren't doing that for autosuspend. Let's do it.
> >
> > Fixes: 9bede63127c6 ("drm/bridge: ti-sn65dsi86: Use pm_runtime autosuspend")
> > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
>
> Hm. I know a few places in drivers where I don't do this :/

It seems to be a very common problem indeed, I haven't seen any driver
yet that uses pm_runtime_dont_use_autosuspend(). We could play a game of
whack-a-mole, but we'll never win. Could this be solved in the runtime
PM framework instead ? pm_runtime_disable() could disable auto-suspend.
If there are legitimate use cases for disabling runtime PM temporarily
without disabling auto-suspend, then a new function designed
specifically for remove() that would take care of cleaning everything up
could be another option.

> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

--
Regards,

Laurent Pinchart