[PATCH] drm/i915/panelreplay: Panel replay workaround with VRR

[Ville Syrjälä]

On Wed, Feb 07, 2024 at 08:05:09PM +0530, Animesh Manna wrote:
> Panel Replay VSC SDP not getting sent when VRR is enabled
> and W1 and W2 are 0. So Program Set Context Latency in
> TRANS_SET_CONTEXT_LATENCY register to at least a value of 1.
> 
> Signed-off-by: Animesh Manna <animesh.manna at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 1b844cac4c58..c1ec78b5b6c5 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -2618,8 +2618,16 @@ static void intel_set_transcoder_timings(const struct intel_crtc_state *crtc_sta
>  	 * TRANS_SET_CONTEXT_LATENCY to configure the pipe vblank start.
>  	 */
>  	if (DISPLAY_VER(dev_priv) >= 13) {
> -		intel_de_write(dev_priv, TRANS_SET_CONTEXT_LATENCY(cpu_transcoder),
> -			       crtc_vblank_start - crtc_vdisplay);
> +		/*
> +		 * WA: Program Set Context Latency in TRANS_SET_CONTEXT_LATENCY register
> +		 * to at least a value of 1 when Panel Replay is enabled with VRR.
> +		 */
> +		if (crtc_state->vrr.enable &&  crtc_state->has_panel_replay &&
> +		    (crtc_vblank_start == crtc_vdisplay))
> +			intel_de_write(dev_priv, TRANS_SET_CONTEXT_LATENCY(cpu_transcoder), 1);

Nak. This needs to match the actual timings we have stored in the mode.

> +		else
> +			intel_de_write(dev_priv, TRANS_SET_CONTEXT_LATENCY(cpu_transcoder),
> +				       crtc_vblank_start - crtc_vdisplay);
>  
>  		/*
>  		 * VBLANK_START not used by hw, just clear it
> -- 
> 2.29.0

-- 
Ville Syrjälä
Intel