[PATCH v2] drm/i915/vrr: Stop writing VRR_CTL_IGN_MAX_SHIFT for MTL onwards

[Nautiyal, Ankit K]

On 4/9/2025 11:19 AM, Jouni Högander wrote:
> According to Bspec VRR_CTL_IGN_MAX_SHIFT doesn't exist for MTL and
> onwards. On LunarLake and onwards Bit 30 is "Mask Block PkgC" instead. Stop
> writing the bit for MeteorLake and onwards
>
> v2: "Ignore Max Shift" bit doesn't exist on MeteorLake either
>
> Bspec: 68925

Perhaps you can add 50508 or 71956 for MTL.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>


> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_vrr.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index 633a66f6b73b..c6565baf815a 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -444,7 +444,10 @@ static u32 trans_vrr_ctl(const struct intel_crtc_state *crtc_state)
>   {
>   	struct intel_display *display = to_intel_display(crtc_state);
>   
> -	if (DISPLAY_VER(display) >= 13)
> +	if (DISPLAY_VER(display) >= 14)
> +		return VRR_CTL_FLIP_LINE_EN |
> +			XELPD_VRR_CTL_VRR_GUARDBAND(crtc_state->vrr.guardband);
> +	else if (DISPLAY_VER(display) >= 13)
>   		return VRR_CTL_IGN_MAX_SHIFT | VRR_CTL_FLIP_LINE_EN |
>   			XELPD_VRR_CTL_VRR_GUARDBAND(crtc_state->vrr.guardband);
>   	else