drm/amd/display: Force FreeSync range minimum on quirky panels

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[why]
Some panels advertise a FreeSync range minimum that does not operate
reliably at the low end:
- X34GS (EDID panel id ACR 0x08AF) reports a minimum that
  can flicker or drop out when the refresh rate approaches the reported
  minimum.
- 34w-30 (EDID panel id LEN 0x66F1) reports a 48 Hz minimum over
  DisplayPort, but the panel fails to light up at that minimum, resulting
  in a black screen. Forcing the minimum to 60 Hz avoids the black screen
  and lets the display light up normally.

[how]
- Add a force_freesync_min_hz field to struct dc_panel_patch.
- Add apply_edid_quirks() cases keyed on the affected panel ids that set
  force_freesync_min_hz (55 Hz for the X34GS, 60 Hz for the G34w-30).
- In amdgpu_dm_update_freesync_caps(), when the quirk is set and the sink
  is otherwise FreeSync capable, clamp the reported VRR range minimum
  (min_vfreq and monitor_range.min_vfreq) to the quirked value.
- Add a KUnit test covering the new quirk.

Reviewed-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@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:

Fangzhi Zuo 2026-07-27 20:37:30 -04:00 • committed by Alex Deucher

parent a34c0e0d24

commit 7ea37c0f06

4 changed files with 48 additions and 0 deletions

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12

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

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18

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

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17

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

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1

drivers/gpu/drm/amd/display/dc/dc_types.h

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