drm/amd/display: add dm_dmub_hw_init KUnit coverage

[WHAT]
Add KUnit coverage for dm_dmub_hw_init() beyond the existing
early-return cases. Introduce reusable fake-DMUB fixtures (fake
dmub_srv/firmware, DMCU/ABM stubs, and adev builders) so the init path
runs without real register access, TTM allocation, or firmware loading.

New cases cover the fake-DMUB success path, unsupported hardware, BSS
data copy, hardware-init failure, auto-load timeout, the APU/DPIA DCN3.5
params, the DCN3.1.x sanity-check ranges, and DMCU/ABM initialization.

Assisted-by: Copilot:Claude-Opus-4.8 GPT-5.5
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@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 2026-07-06 09:16:18 -06:00 • committed by Alex Deucher
commit f1d518d1b7