drm/amd/display: fix dmub access race condition

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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>

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This commit is contained in:

Aurabindo Pillai 2025-07-21 11:03:39 -04:00 • committed by Alex Deucher

parent fd20627c74

commit c210b757b4

2 changed files with 63 additions and 6 deletions

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55

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

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14

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

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