drm/amd/display: Test DMUB reg callbacks

Browse source

[WHAT]
Add KUnit tests for amdgpu_dm_dmub_reg_read() and
amdgpu_dm_dmub_reg_write(), the register accessors the DMUB service is
created with.

[HOW]
Both accessors reach the hardware through cgs_read_register() and
cgs_write_register(), which dispatch through the ops table at the start
of struct cgs_device. Add a fake CGS device that records the offset and
value of each access, so the callbacks can be driven without real MMIO.

The test writes a value through the write callback and reads it back
through the read callback, confirming both forward to the DC context of
the device passed as their opaque user context.

Assisted-by: Copilot:Claude-Opus-5
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Alex Hung 2026-08-11 11:45:42 -06:00 • committed by Alex Deucher

parent 99c52fb371

commit 9ebd70b746

3 changed files with 101 additions and 4 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

8

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.c

View file

2

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_dmub.h

View file

95

drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_dmub_test.c

View file