drm/amd/display: Add KUnit tests for link_lock and psp SRM helpers

Cover link_lock() across all links (lock then unlock) and the
max_link == 0 no-op path, checking each per-link mutex ends in
the expected state.

Also cover the psp_get_srm() and psp_set_srm() guard paths when
the HDCP TA context is uninitialized: psp_get_srm() returns NULL
and psp_set_srm() returns -EINVAL, both leaving their output
parameters untouched. The post-guard paths invoke real PSP
firmware and are not unit-testable in UML.

Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Bhawanpreet Lakha 2026-07-10 14:05:41 -04:00 • committed by Alex Deucher
commit fad644eab1
3 changed files with 140 additions and 3 deletions