[PATCH 0/1][SRU][N][O] The system hangs after resume with thunderbolt monitor(AMD GPU [1002:1900])

[Chia-Lin Kao (AceLan)]

BugLink: https://bugs.launchpad.net/bugs/2083182

[Impact]
The system hangs on blackscreen with thunderbolt monitor while resume from suspend state.

[Fix]
The TBT monitor HPD will be triggered during the resume procedure
and call the drm_client_modeset_probe() while
struct drm_connector connector->dev->master is NULL.

It will mess up the pipe topology after resume.

AMD submitted a patch to fix this issue.
https://lore.kernel.org/all/20240927170103.102180-3-Jerry.Zuo@amd.com/T/#e868f6b967ec79ae85c5a8a446be9b5d5c97e5427

[Test case]
1. Boot to OS
2. Plug thunderbolt monitor to the system.
3. Enter suspend
4. Press the power button to resume from suspend
5. Should not hang

[Where problems could occur]
Pretty low chance to introduce any regressions.
The patch won't do anything bad to the system while resuming,
the probing will be done after resumed.

Tom Chung (1):
  UBUNTU: SAUCE: drm/amd/display: Fix system hang while resume with TBT
    monitor

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++++
 1 file changed, 6 insertions(+)

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2.43.0