Hi, On Tue, Sep 5, 2023 at 1:16 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > > Paul, > > On Mon, Sep 4, 2023 at 2:15 AM Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote: > > > > Hi Douglas, > > > > Le vendredi 01 septembre 2023 à 16:41 -0700, Douglas Anderson a écrit : > > > Based on grepping through the source code this driver appears to be > > > missing a call to drm_atomic_helper_shutdown() at system shutdown > > > time. Among other things, this means that if a panel is in use that > > > it > > > won't be cleanly powered off at system shutdown time. > > > > > > The fact that we should call drm_atomic_helper_shutdown() in the case > > > of OS shutdown/restart comes straight out of the kernel doc "driver > > > instance overview" in drm_drv.c. > > > > > > Since this driver uses the component model and shutdown happens at > > > the > > > base driver, we communicate whether we have to call > > > drm_atomic_helper_shutdown() by seeing if drvdata is non-NULL. > > > > > > Suggested-by: Maxime Ripard <mripard@xxxxxxxxxx> > > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > > > > LGTM. > > Acked-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx> > > Thanks for the Ack! Would you expect this patch to land through > "drm-misc", or do you expect it to go through some other tree? > Running: > > ./scripts/get_maintainer.pl --scm -f drivers/gpu/drm/ingenic/ingenic-drm-drv.c > > ...does not show that this driver normally goes through drm-misc, but > it also doesn't show that it goes through any other tree so maybe it's > just an artifact of the way it's tagged in the MAINTAINERS file? If > it's fine for this to go through drm-misc, I'll probably land it (with > your Ack and Maxime's Review) sooner rather than later just to make > this patch series less unwieldy. > > > > > --- > > > This commit is only compile-time tested. > > > > > > NOTE: this patch touches a lot more than other similar patches since > > > the bind() function is long and we want to make sure that we unset > > > the > > > drvdata if bind() fails. > > > > > > While making this patch, I noticed that the bind() function of this > > > driver is using "devm" and thus assumes it doesn't need to do much > > > explicit error handling. That's actually a bug. As per kernel docs > > > [1] > > > "the lifetime of the aggregate driver does not align with any of the > > > underlying struct device instances. Therefore devm cannot be used and > > > all resources acquired or allocated in this callback must be > > > explicitly released in the unbind callback". Fixing that is outside > > > the scope of this commit. > > > > > > [1] https://docs.kernel.org/driver-api/component.html > > > > > > > Noted, thanks. > > FWIW, I think that at least a few other DRM drivers handle this by > doing some of their resource allocation / acquiring in the probe() > function and then only doing things in the bind() that absolutely need > to be in the bind. ;-) I've been collecting patches that are ready to land in drm-misc but, right now, I'm not taking this patch since I didn't get any clarification of whether it should land through drm-misc or somewhere else. -Doug
