Hi, On Tue, Dec 5, 2023 at 5:40 AM Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > > On Tue, Dec 05, 2023 at 02:31:24PM +0100, Geert Uytterhoeven wrote: > > On Tue, Dec 5, 2023 at 1:16 PM Laurent Pinchart 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 > > That looks like what Doug mentioned should be removed in the commit > message of this patch (a confirmation would be nice). It should be fine > for now. Yup, this is completely expected right now and is actually a _good_ sign that your patch is doing what it should be. We unfortunately can't remove the panel_simple_shutdown() until all DRM modeset drivers (or at least all the ones that could be used w/ panel_simple) are properly calling drm_helper_force_disable_all(), though. -Doug
