Re: [PATCH 2/2] drm/i915/display: allow eDP VRR when EDID has adaptive sync range

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Apr 15, 2026 at 09:06:26AM -0400, Jake S wrote:
> intel_vrr_is_capable() currently hard-gates eDP VRR on the VBT (Video
> BIOS Table) vrr flag. Many OEMs ship laptops with VRR-capable eDP OLED
> panels but do not set the VRR flag in the VBT, making VRR impossible
> on Linux even though the hardware supports it and works on Windows.
> 
> Relax the eDP check: if the VBT flag is not set but the EDID provides
> a valid monitor range with delta > 10Hz (now also populated from
> DisplayID Adaptive Sync blocks by the previous patch), allow VRR. The
> existing checks for DPCD Ignore MSA and monitor range delta still apply.

AFAICS the Windows driver does respect that VBT bit. So we should too.

> 
> This mirrors the approach taken by amdgpu, which has its own EDID-based
> VRR fallback (parse_edid_displayid_vrr) for exactly this class of panel.
> 
> Tested on Dell XPS 2026 (Intel Panther Lake / xe driver, LG Display
> OLED eDP, 3200x2000, VRR 20-120Hz confirmed via vblank event tracing).
> 
> Signed-off-by: Jake S <j@metarealtyinc.ca>
> ---
>  gpu/drm/i915/display/intel_vrr.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/gpu/drm/i915/display/intel_vrr.c b/gpu/drm/i915/display/intel_vrr.c
> index bea0057..f527471 100644
> --- a/gpu/drm/i915/display/intel_vrr.c
> +++ b/gpu/drm/i915/display/intel_vrr.c
> @@ -47,7 +47,12 @@ bool intel_vrr_is_capable(struct intel_connector *connector)
>  	 */
>  	switch (connector->base.connector_type) {
>  	case DRM_MODE_CONNECTOR_eDP:
> -		if (!connector->panel.vbt.vrr)
> +		/*
> +		 * Prefer VBT flag, but fall back to EDID monitor range
> +		 * for panels where OEM firmware omits the VBT VRR flag.
> +		 */
> +		if (!connector->panel.vbt.vrr &&
> +		    !(info->monitor_range.max_vfreq - info->monitor_range.min_vfreq > 10))
>  			return false;
>  		fallthrough;
>  	case DRM_MODE_CONNECTOR_DisplayPort:
> -- 
> 2.53.0

-- 
Ville Syrjälä
Intel