Hi,
On Tue, Sep 5, 2023 at 1:16 PM Doug Anderson <[email protected]> wrote:
>
> Paul,
>
> On Mon, Sep 4, 2023 at 2:15 AM Paul Cercueil <[email protected]> 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 <[email protected]>
> > > Signed-off-by: Douglas Anderson <[email protected]>
> >
> > LGTM.
> > Acked-by: Paul Cercueil <[email protected]>
>
> 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
Hi Doug,
Le mercredi 13 septembre 2023 à 09:25 -0700, Doug Anderson a écrit :
> Hi,
>
> On Tue, Sep 5, 2023 at 1:16 PM Doug Anderson <[email protected]>
> wrote:
> >
> > Paul,
> >
> > On Mon, Sep 4, 2023 at 2:15 AM Paul Cercueil <[email protected]>
> > 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 <[email protected]>
> > > > Signed-off-by: Douglas Anderson <[email protected]>
> > >
> > > LGTM.
> > > Acked-by: Paul Cercueil <[email protected]>
> >
> > 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.
Sorry, you can take it in drm-misc, yes.
Cheers,
-Paul