[RFC PATCH 0/2] drm/amd/display: switch amdgpu_dm_connector to

[Melissa Wen]

Hi,

I'm debugging a null-pointer dereference when running
igt at kms_connector_force_edid and the way I found to solve the bug is to
stop using raw edid handler in amdgpu_connector_funcs_force and
create_eml_sink in favor of managing resouces via sruct drm_edid helpers
(Patch 1). The proper solution seems to be switch amdgpu_dm_connector
from struct edid to struct drm_edid and avoid the usage of different
approaches in the driver (Patch 2). However, doing it implies a good
amount of work and validation, therefore I decided to send this RFC
first to collect opinions and check if there is any parallel work on
this side. It's a working in progress.

The null-pointer error trigger by the igt at kms_connector_force_edid test
was introduced by:
- e54ed41620f ("drm/amd/display: Remove unwanted drm edid references")

You can check the error trace in the first patch.

This series was tested with kms_hdmi_inject and kms_force_connector. No
null-pointer error, kms_hdmi_inject is successul and kms_force_connector
is sucessful after the second execution - the force-edid subtest
still fails in the first run (I'm still investigating).

There is also a couple of cast warnings to be addressed - I'm looking
for the best replacement. 

I appreciate any feedback and testing.

Melissa

Melissa Wen (2):
  drm/amd/display: fix null-pointer dereference on edid reading
  drm/amd/display: switch amdgpu_dm_connector to use struct drm_edid

 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 78 ++++++++++---------
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  4 +-
 .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c |  9 ++-
 .../display/amdgpu_dm/amdgpu_dm_mst_types.c   | 23 +++---
 4 files changed, 60 insertions(+), 54 deletions(-)

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2.43.0