[PATCH v11 0/7] User readable error codes on atomic_ioctl failure

[Arun R Murthy <arun.r.murthy@intel.com>]

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

[DRAFT] KWin changes are pushed for review @
https://invent.kde.org/plasma/kwin/-/merge_requests/8991

    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                  | 56 +++++++++++++++++
 7 files changed, 184 insertions(+), 37 deletions(-)
---
base-commit: 65b94118bc585aefc7095c0e9554c3bb12d98a69
change-id: 20250728-atomic-c9713fd357e4

Best regards,
-- 
Arun R Murthy <arun.r.murthy@intel.com>