[PATCH 0/6] drm: enforce rules for drm_atomic_helper_check_modeset()

[Dmitry Baryshkov]

As pointed out by Simona, the drm_atomic_helper_check_modeset() and
drm_atomic_helper_check() require the former function is rerun if the
driver's callbacks modify crtc_state->mode_changed. MSM is one of the
drivers which failed to follow this requirement.

As suggested by Simona, implement generic code to verify that the
drivers abide to those requirement and rework MSM driver to follow that
restrictions.

There are no dependencies between core and MSM parts, so they can go
separately via corresponding trees.

Reported-by: Simona Vetter <simona.vetter at ffwll.ch>
Link: https://lore.kernel.org/dri-devel/ZtW_S0j5AEr4g0QW@phenom.ffwll.local/
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
Dmitry Baryshkov (6):
      drm/atomic-helper: document drm_atomic_helper_check() restrictions
      drm/atomic: prepare to check that drivers follow restrictions for needs_modeset
      drm/msm/dpu: don't use active in atomic_check()
      drm/msm/dpu: move needs_cdm setting to dpu_encoder_get_topology()
      drm/msm/dpu: simplify dpu_encoder_get_topology() interface
      drm/msm/dpu: don't set crtc_state->mode_changed from atomic_check()

 drivers/gpu/drm/drm_atomic.c                |  3 +
 drivers/gpu/drm/drm_atomic_helper.c         | 86 ++++++++++++++++++++++++++---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  4 --
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 82 +++++++++++++++++----------
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h |  4 ++
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 26 +++++++++
 drivers/gpu/drm/msm/msm_atomic.c            | 13 ++++-
 drivers/gpu/drm/msm/msm_kms.h               |  7 +++
 include/drm/drm_atomic.h                    | 10 ++++
 9 files changed, 192 insertions(+), 43 deletions(-)
---
base-commit: b72747fdde637ebf52e181671bf6f41cd773b3e1
change-id: 20241222-drm-dirty-modeset-88079bd27ae6

Best regards,
-- 
Dmitry Baryshkov <dmitry.baryshkov at linaro.org>