Hi Laurent, On Tue, Dec 5, 2023 at 1:16 PM Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > On Tue, Dec 05, 2023 at 12:30:02PM +0100, Geert Uytterhoeven wrote: > > From: Douglas Anderson <dianders@xxxxxxxxxxxx> > > > > 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 <mripard@xxxxxxxxxx> > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > > 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 <geert+renesas@xxxxxxxxx> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> 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 -- geert@xxxxxxxxxxxxxx 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