linux-kernel - Re: [PATCH v4] drm/tilcdc: Fix removal actions in case of failed probe

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Message-ID: <CAD=FV=WrQpa3G0ggSMiJG8RnT45zCLug2YKTTgPfNrzAoQU98Q@mail.gmail.com>
Date: Mon, 8 Dec 2025 14:21:09 -0800
From: Doug Anderson <dianders@...omium.org>
To: Kory Maincent <kory.maincent@...tlin.com>
Cc: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>, Maxime Ripard <mripard@...nel.org>, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
	Bajjuri Praneeth <praneeth@...com>, Luca Ceresoli <luca.ceresoli@...tlin.com>, 
	Louis Chauvet <louis.chauvet@...tlin.com>, stable@...r.kernel.org, 
	thomas.petazzoni@...tlin.com, Jyri Sarha <jyri.sarha@....fi>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Thomas Zimmermann <tzimmermann@...e.de>, 
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Subject: Re: [PATCH v4] drm/tilcdc: Fix removal actions in case of failed probe

Hi,

On Mon, Dec 1, 2025 at 10:10 AM Doug Anderson <dianders@...omium.org> wrote:
>
> Hi,
>
> On Tue, Nov 25, 2025 at 1:06 AM Kory Maincent <kory.maincent@...tlin.com> wrote:
> >
> > From: "Kory Maincent (TI.com)" <kory.maincent@...tlin.com>
> >
> > The drm_kms_helper_poll_fini() and drm_atomic_helper_shutdown() helpers
> > should only be called when the device has been successfully registered.
> > Currently, these functions are called unconditionally in tilcdc_fini(),
> > which causes warnings during probe deferral scenarios.
> >
> > [    7.972317] WARNING: CPU: 0 PID: 23 at drivers/gpu/drm/drm_atomic_state_helper.c:175 drm_atomic_helper_crtc_duplicate_state+0x60/0x68
> > ...
> > [    8.005820]  drm_atomic_helper_crtc_duplicate_state from drm_atomic_get_crtc_state+0x68/0x108
> > [    8.005858]  drm_atomic_get_crtc_state from drm_atomic_helper_disable_all+0x90/0x1c8
> > [    8.005885]  drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x90/0x144
> > [    8.005911]  drm_atomic_helper_shutdown from tilcdc_fini+0x68/0xf8 [tilcdc]
> > [    8.005957]  tilcdc_fini [tilcdc] from tilcdc_pdev_probe+0xb0/0x6d4 [tilcdc]
> >
> > Fix this by rewriting the failed probe cleanup path using the standard
> > goto error handling pattern, which ensures that cleanup functions are
> > only called on successfully initialized resources. Additionally, remove
> > the now-unnecessary is_registered flag.
> >
> > Cc: stable@...r.kernel.org
> > Fixes: 3c4babae3c4a ("drm: Call drm_atomic_helper_shutdown() at shutdown/remove time for misc drivers")
> > Signed-off-by: Kory Maincent (TI.com) <kory.maincent@...tlin.com>
> > ---
> >
> > I'm working on removing the usage of deprecated functions as well as
> > general improvements to this driver, but it will take some time so for
> > now this is a simple fix to a functional bug.
> >
> > Change in v4:
> > - Fix an unused label warning reported by the kernel test robot.
> >
> > Change in v3:
> > - Rewrite the failed probe clean up path using goto
> > - Remove the is_registered flag
> >
> > Change in v2:
> > - Add missing cc: stable tag
> > - Add Swamil reviewed-by
> > ---
> >  drivers/gpu/drm/tilcdc/tilcdc_crtc.c |  2 +-
> >  drivers/gpu/drm/tilcdc/tilcdc_drv.c  | 53 ++++++++++++++++++----------
> >  drivers/gpu/drm/tilcdc/tilcdc_drv.h  |  2 +-
> >  3 files changed, 37 insertions(+), 20 deletions(-)
>
> Seems reasonable to me. I did a once-over and based on code inspection
> it looks like things are being reversed properly. I agree this should
> probably land to fix the regression while waiting for a bigger
> cleanup.
>
> Reviewed-by: Douglas Anderson <dianders@...omium.org>
>
> This fixup has been sitting out there for a while. Who is the right
> person to apply it? If nobody else does and there are no objections, I
> can apply it to "fixes" next week...

Pushed to drm-misc-fixes:

[1/1] drm/tilcdc: Fix removal actions in case of failed probe
      commit: a585c7ef9cabda58088916baedc6573e9a5cd2a7