Re: [PATCH 0/2] drm/amd/display: Fix FreeSync infopacket refresh rates above 255 Hz

[Harry Wentland <harry.wentland@amd.com>]

On 10/31/26 00:18, Cooper Morgan wrote:
> On my MSI MAG 271QPX32 (320Hz QD-OLED over DP 1.4, RX 9070 XT), 320Hz
> looks like a 720p image stretched to fill the screen whenever
> Adaptive-Sync is on in the monitor's OSD. Custom modes at 305-315Hz put
> it into its self-test pattern instead. Windows is fine on the same
> machine and cable. It's the same bug as
> https://gitlab.freedesktop.org/drm/amd/-/issues/5988, where an LG at
> 280Hz shows up as 24Hz.
>
> The cause is the v1 FreeSync infopacket, which native DP sinks get
> unless they're a whitelisted PCON or support Replay. It stores the min
> and max refresh in one byte each, so 320 wraps to 64.
>
> Patch 1 caps those bytes at 255 instead of letting them wrap. With the
> EDID range capped at 255, the monitor gets the same bytes patch 1 sends,
> and the picture was correct, so I tagged it for stable.
>
> Patch 2 sends the v3 packet to sinks that advertise AMD VSDB v3 and go
> above 255Hz, so VRR gets the full range. Sinks at 255Hz and below are
> unchanged.
>
> This builds on what sunryze and oystersuki worked out in that issue.
> sunryze found that the VSDB version was only saved for Replay sinks on
> DP and tested sending v3 on their LG. oystersuki suggested pairing that
> with a 255 cap for sinks that don't advertise v3. Neither has a public
> email, so they're credited here instead of with tags.
>
> Tested with the series backported to 7.2.13: 320Hz looks right, and
> with VRR on, the monitor's refresh readout follows frame caps at 300,
> 270, 240, and 100fps. Both patches add KUnit tests.

Series is
Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

>
> Cooper Morgan (2):
>   drm/amd/display: Saturate refresh rates in v1/v2 FreeSync infopackets
>   drm/amd/display: Use FreeSync v3 infopacket for sinks above 255 Hz
>
>  .../display/amdgpu_dm/amdgpu_dm_connector.c   |   2 +-
>  .../display/amdgpu_dm/amdgpu_dm_freesync.c    |   7 ++
>  .../tests/amdgpu_dm_connector_test.c          |  25 ++++
>  .../amdgpu_dm/tests/amdgpu_dm_freesync_test.c | 116 ++++++++++++++++++
>  .../amd/display/modules/freesync/freesync.c   |  12 +-
>  5 files changed, 158 insertions(+), 4 deletions(-)