drm/amd/display: Add stressed peak bandwidth probe with DMA contention

[Why]
Peak-bandwidth-under-contention validation currently needs an
external tool to manufacture memory contention while querying
peak bandwidth. Expose this as an explicit probe variant so the
driver can generate that contention itself.

[How]
Add a new probe type that builds the same gated perfmon sequence
as the plain peak-BW probe, with a DMA copy of the current
surface into a scratch buffer inserted before the measurement
window to synthesize a competing memory client. Move the scratch
buffer fields onto the base resource pool struct instead of an
ASIC-specific subclass, and reject the probe with a new status
code when the buffer was never allocated. Also fixes a stack-
corruption bug where a local variable's address was captured by
a deferred callback and used after the local went out of scope,
and a missing NULL check on a similar output parameter used by
an early-return path.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Wenjing Liu 2026-08-05 16:41:35 -04:00 • committed by Alex Deucher
commit 11f8fe9480
11 changed files with 106 additions and 4 deletions