drm/amd/display: fix dmub access race condition

Browse source

[ Upstream commit c210b757b4 ]

Accessing DC from amdgpu_dm is usually preceded by acquisition of
dc_lock mutex. Most of the DC API that DM calls are under a DC lock.
However, there are a few that are not. Some DC API called from interrupt
context end up sending DMUB commands via a DC API, while other threads were
using DMUB. This was apparent from a race between calls for setting idle
optimization enable/disable and the DC API to set vmin/vmax.

Offload the call to dc_stream_adjust_vmin_vmax() to a thread instead
of directly calling them from the interrupt handler such that it waits
for dc_lock.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Aurabindo Pillai 2025-07-21 11:03:39 -04:00 • committed by Greg Kroah-Hartman

parent 2384304de3

commit 09250b6e73

2 changed files with 63 additions and 6 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

55

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

View file

14

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

View file