[PATCH v3 0/8] drm/msm: fix SMMU fault dumps

[Dmitry Baryshkov]

In several cases the drm/msm can cause an SMMU fault on modesetting (due
to the display controller still scanning the BO which is being
unmapped). Fix the cases which I stumbled upon, together with the issues
found while chasing them: hardware block pointers surviving the
reservation which handed them out, and the teardown of a KMS which was
never fully set up.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
---
Changes in v3:
- Initialise the framebuffer's lock and dirtyfb count before
  drm_framebuffer_init() publishes the framebuffer (Sashiko)
- New patch: unwind msm_drm_kms_init() on failure rather than handing a
  half-initialised kms to msm_drm_kms_uninit() (prompted by Sashiko)
- Drop the pin count from the deferred unpin work rather than from
  ->cleanup_fb(), so a framebuffer scanned out by several crtcs stays
  pinned until the last of them has passed a vblank (Sashiko)
- Defer each retired framebuffer with its own drm_vblank_work, as i915
  does for cursor framebuffers, instead of a per-crtc drm_flip_work: the
  release no longer takes a detour through kms->wq, and nothing needs
  setting up or tearing down in the kms init path
- Release the framebuffers still pending on a crtc by hand when its vblank
  is switched off; its interface is already disabled by then, so no
  further vblank arrives to run the work
- New patch: clear the DSC blocks left by a previous reservation, the same
  bug as the DSPP one (Sashiko)
- Link to v2: https://patch.msgid.link/20260908-fd-kms-fix-smmu-v2-0-9391815742a8@xxxxxxxxxxxxxxxx

Changes in v2:
- New patch: lock the framebuffer pin state, it was updated locklessly
  (Sashiko)
- Do not defer the release on an inactive crtc, it was leaked there
  (Sashiko)
- Flush retired framebuffers from msm_drm_kms_uninit(), before kms->vm is
  dropped, and only for crtcs which have a vblank work (Sashiko)
- Clean the flip works up after destroy_workqueue() (Sashiko)
- Fixed the long-standing issue of the msm driver roguely setting
  allow_modeset, which started to manifest in timeouts and SMMU errors.
- Link to v1: https://patch.msgid.link/20260903-fd-kms-fix-smmu-v1-0-608d02491666@xxxxxxxxxxxxxxxx

To: Rob Clark <robin.clark@xxxxxxxxxxxxxxxx>
To: Dmitry Baryshkov <lumag@xxxxxxxxxx>
To: Abhinav Kumar <abhinav.kumar@xxxxxxxxx>
To: Jessica Zhang <jesszhan0024@xxxxxxxxx>
To: Sean Paul <sean@xxxxxxxxxx>
To: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
To: David Airlie <airlied@xxxxxxxxx>
To: Simona Vetter <simona@xxxxxxxx>
To: Antonino Maniscalco <antomani103@xxxxxxxxx>
To: Kalyan Thota <quic_kalyant@xxxxxxxxxxx>
To: Federico Amedeo Izzo <federico@xxxxxxxx>
To: Helen Koike <helen.fornazier@xxxxxxxxx>
To: Vignesh Raman <vignesh.raman@xxxxxxxxxxxxx>
To: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
To: Maxime Ripard <mripard@xxxxxxxxxx>
To: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: linux-arm-msm@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: freedreno@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>

---
Dmitry Baryshkov (8):
      drm/msm: serialise framebuffer pin state
      drm/msm: fix framebuffer pin refcount leak on prepare failure
      drm/msm: unwind msm_drm_kms_init() on failure
      drm/msm: release scanout framebuffers only after a vblank
      drm/msm/dpu: clear the DSPP pointer when no DSPP is assigned
      drm/msm/dpu: clear the DSC blocks left by a previous reservation
      drm/msm/dpu: only reassign resources when the encoder is reprogrammed
      drm/ci: mark pixel-format tests as passing on SC7180

 .../xfails/msm-sc7180-trogdor-kingoftown-fails.txt |   2 -
 .../msm-sc7180-trogdor-lazor-limozeen-fails.txt    |   2 -
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c           |  34 ++++-
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c        |   7 +-
 .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c    |   2 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c          |   3 +-
 drivers/gpu/drm/msm/disp/mdp4/mdp4_crtc.c          |   2 +-
 drivers/gpu/drm/msm/disp/mdp4/mdp4_plane.c         |   2 +-
 drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c          |   2 +-
 drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c         |   2 +-
 drivers/gpu/drm/msm/msm_atomic.c                   |  17 +--
 drivers/gpu/drm/msm/msm_drv.c                      |  27 +++-
 drivers/gpu/drm/msm/msm_drv.h                      |   4 +-
 drivers/gpu/drm/msm/msm_fb.c                       |  78 +++++++++--
 drivers/gpu/drm/msm/msm_kms.c                      | 151 +++++++++++++++++++--
 drivers/gpu/drm/msm/msm_kms.h                      |  16 +++
 16 files changed, 283 insertions(+), 68 deletions(-)
---
base-commit: 140b13475302601368c0cf4e193e66126a49feb3
change-id: 20260902-fd-kms-fix-smmu-2d4baaf460b0

Best regards,
--  
With best wishes
Dmitry