drm/edid: parse HDMI 2.1 gaming (ALLM/VRR) capabilities from HF-VSDB

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Parse the HDMI 2.1 gaming-related capabilities advertised in the HDMI
Forum VSDB (HF-VSDB) and expose them through struct drm_hdmi_info so
drivers can consume them.

Add struct drm_hdmi_vrr_cap describing the sink's VRR capabilities: Fast
VActive (Quick Frame Transport), Negative M VRR, Cinema VRR, MDelta, and
the VRRmin/VRRmax range, together with a "supported" flag derived from
that range. Add the fapa_start_location and allm (Auto Low Latency Mode)
flags to struct drm_hdmi_info.

drm_parse_hdmi_gaming_info() reads byte 8 of the HF-VSDB for the
FAPA/ALLM/FVA/CNMVRR/CinemaVRR/MDelta flags and bytes 9-10 for
VRRmin/VRRmax. Per HDMI 2.1, VRR is considered supported when VRRmin is
within 1-48 and VRRmax is either 0 (maximum based on the video mode) or
>= 100. It is invoked from drm_parse_hdmi_forum_scds(), and the parsed
values are logged for debugging.

Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Tested-by: Bernhard Berger <bernhard.berger@gmail.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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This commit is contained in:

Tomasz Pakuła 2026-07-24 15:34:43 -04:00 • committed by Alex Deucher

parent d8a0affd20

commit 6675c4642b

2 changed files with 89 additions and 0 deletions

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42

drivers/gpu/drm/drm_edid.c

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47

include/drm/drm_connector.h

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