drm/amd/display: Fix DCN6 peak bandwidth measurement overshoot

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[Why]
The out-of-order (peak prefetch) bandwidth probe could report
bandwidth far above the physical clock ceiling. The data and
duration counters could latch on different edges of the shared
stop event, and very short measurement windows amplified refclk
tick quantization into large relative errors.

[How]
Add a dedicated counter (2) that generates the single stop event
both the data counter (1) and duration counter (4) key off of, so
they always latch on the same edge. Reject samples where the data
counter overshoots the generator's target, or where the duration
is too short to trust. Also drop the single-timing-group
restriction on the peak-BW probe.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Wenjing Liu 2026-07-29 17:43:33 -04:00 • committed by Alex Deucher

parent ab07c95def

commit 435f359a23

2 changed files with 75 additions and 31 deletions

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96

drivers/gpu/drm/amd/display/dc/hubbub/dcn60/dcn60_hubbub.c

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10

drivers/gpu/drm/amd/display/dc/hwss/dcn60/dcn60_hwseq.c

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