Re: [PATCH v10 0/7] User readable error codes on atomic_ioctl failure

Ville Syrjälä
2026-02-24T07:07:23Z

On Mon, Feb 23, 2026 at 03:37:39PM +0530, Murthy, Arun R wrote:
> Any other comments/feedback on this?

Having random strings as uabi seems like a bad idea.
How would you make sure those are never changed?

>
> Thanks and Regards,
> Arun R Murthy
> -------------------
>
> On 23-02-2026 14:45, Arun R Murthy wrote:
> > EDITME: Imported from f20260210-atomic-v9-5-525c88fd2402@intel.com
> > Please review before sending.
> >
> > The series focuses on providing a user readable error value on a failure
> > in drm_atomic_ioctl(). Usually -EINVAL is returned in most of the error
> > cases and it is difficult for the user to decode the error and get to
> > know the real cause for the error. If user gets to know the reason for
> > the error then corrective measurements can be taken up.
> >
> > User will have to check for the capability
> > DRM_CAP_ATOMIC_ERROR_REPORTING before using this feature so as to ensure
> > that the driver supports failure reporting.
> >
> > TODO: driver specific error codes are to be added and will be done in
> > the follow-up patches.
> >
> > TODO: Once the series is merged the element 'reserved' used for sending
> > the failure code in struct drm_mode_atomic is to changed to err_code.
> >
> > The IGT related changes are pushed for review @
> > https://patchwork.freedesktop.org/series/153330/
> >
> > [RFC] changes for libdrm pushed for review @
> > https://gitlab.freedesktop.org/mesa/libdrm/-/merge_requests/450
> >
> > To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > To: suraj.kandpal@intel.com>
> > To: Maxime Ripard <mripard@kernel.org>
> > To: Thomas Zimmermann <tzimmermann@suse.de>
> > To: David Airlie <airlied@gmail.com>
> > To: Simona Vetter <simona@ffwll.ch>
> > To: Jani Nikula <jani.nikula@linux.intel.com>
> > To: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > To: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> > To: Tvrtko Ursulin <tursulin@ursulin.net>
> > To: xaver.hugl@kde.org
> > To: harry.wentland@amd.com
> > To: uma.shankar@intel.com
> > To: louis.chauvet@bootlin.com
> > To: naveen1.kumar@intel.com
> > To: ramya.krishna.yella@intel.com
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: intel-gfx@lists.freedesktop.org
> > Cc: intel-xe@lists.freedesktop.org
> > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> >
> > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> > ---
> > Changes in v9:
> > - EDITME: describe what is new in this series revision.
> > - EDITME: use bulletpoints and terse descriptions.
> > - Link to v8: https://lore.kernel.org/r/20260129-atomic-v8-0-4cb7b0faa051@intel.com
> >
> > ---
> > Arun R Murthy (7):
> > drm: Define user readable error codes for atomic ioctl
> > drm/atomic: Add error_code element in atomic_state
> > drm/atomic: Call complete_signaling only if prepare_signaling is done
> > drm/atomic: Allocate atomic_state at the beginning of atomic_ioctl
> > drm/atomic: Return user readable error in atomic_ioctl
> > drm/i915/display: Error codes for async flip failures
> > drm: Introduce DRM_CAP_ATOMIC_ERROR_REPORTING
> >
> > drivers/gpu/drm/drm_atomic.c | 31 ++++++++++
> > drivers/gpu/drm/drm_atomic_uapi.c | 89 ++++++++++++++++++++--------
> > drivers/gpu/drm/drm_ioctl.c | 3 +
> > drivers/gpu/drm/i915/display/intel_display.c | 25 ++++----
> > include/drm/drm_atomic.h | 10 ++++
> > include/uapi/drm/drm.h | 7 +++
> > include/uapi/drm/drm_mode.h | 37 ++++++++++++
> > 7 files changed, 165 insertions(+), 37 deletions(-)
> > ---
> > base-commit: cec43d5c2696af219fc2ef71dd7e93db48c80f66
> > change-id: 20250728-atomic-c9713fd357e4
> >
> > Best regards,

--
Ville Syrjälä
Intel