Hi Laurent,
On Tue, Dec 5, 2023 at 1:16 PM Laurent Pinchart
<[email protected]> wrote:
> On Tue, Dec 05, 2023 at 12:30:02PM +0100, Geert Uytterhoeven wrote:
> > From: Douglas Anderson <[email protected]>
> >
> > Based on grepping through the source code, this driver appears to be
> > missing a call to drm_atomic_helper_shutdown() at system shutdown time.
> > This is important because drm_helper_force_disable_all() will cause
> > panels to get disabled cleanly which may be important for their power
> > sequencing. Future changes will remove any custom powering off in
> > individual panel drivers so the DRM drivers need to start getting this
> > right.
> >
> > The fact that we should call drm_atomic_helper_shutdown() in the case of
> > OS shutdown comes straight out of the kernel doc "driver instance
> > overview" in drm_drv.c.
> >
> > Suggested-by: Maxime Ripard <[email protected]>
> > Signed-off-by: Douglas Anderson <[email protected]>
> > Link:
> > https://lore.kernel.org/r/20230901164111.RFT.15.Iaf638a1d4c8b3c307a6192efabb4cbb06b195f15@changeid
> > [geert: s/drm_helper_force_disable_all/drm_atomic_helper_shutdown/]
> > [geert: shmob_drm_remove() already calls drm_atomic_helper_shutdown]
> > Signed-off-by: Geert Uytterhoeven <[email protected]>
>
> Reviewed-by: Laurent Pinchart <[email protected]>
Thanks!
> > Panel-simple does print two new warnings:
> >
> > +panel-simple panel: Skipping disable of already disabled panel
> > +panel-simple panel: Skipping unprepare of already unprepared panel
>
> Have you investigated where this comes from ?
Meh, I knew I forgot something ;-)
The panel is unprepared and disabled a first time from shmob_drm's
.shutdown() callback:
shmob_drm_shutdown
drm_atomic_helper_shutdown
drm_atomic_helper_disable_all
drm_atomic_commit
drm_atomic_helper_commit
commit_tail
drm_atomic_helper_commit_tail
drm_atomic_helper_commit_modeset_disables
disable_outputs
drm_atomic_bridge_chain_disable
drm_panel_disable
drm_atomic_bridge_chain_post_disable
drm_panel_unprepare
And a second time from simple_panel's .shutdown() callback():
panel_simple_platform_shutdown
panel_simple_shutdown
drm_panel_disable
drm_panel_unprepare
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
