[PATCH v2] drm/i915/panelreplay: Panel replay workaround with VRR

[Ville Syrjälä]

On Fri, Feb 09, 2024 at 09:13:00PM +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.
> 
> HSD: 14015406119
> 
> v1: Initial version.
> v2: Update timings stored in adjusted_mode struct. [Ville]
> 
> Signed-off-by: Animesh Manna <animesh.manna at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_vblank.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c b/drivers/gpu/drm/i915/display/intel_vblank.c
> index baf7354cb6e2..2e11629e4e9f 100644
> --- a/drivers/gpu/drm/i915/display/intel_vblank.c
> +++ b/drivers/gpu/drm/i915/display/intel_vblank.c
> @@ -552,6 +552,19 @@ void intel_crtc_update_active_timings(const struct intel_crtc_state *crtc_state,
>  		adjusted_mode.crtc_vtotal = crtc_state->vrr.vmax;
>  		adjusted_mode.crtc_vblank_end = crtc_state->vrr.vmax;
>  		adjusted_mode.crtc_vblank_start = intel_vrr_vmin_vblank_start(crtc_state);
> +
> +		/*
> +		 * WA: HSD-14015406119
> +		 * Program Set Context Latency in TRANS_SET_CONTEXT_LATENCY register
> +		 * to at least a value of 1 when Panel Replay is enabled with VRR.
> +		 * Value for TRANS_SET_CONTEXT_LATENCY is calculated by substracting
> +		 * crtc_vdisplay from crtc_vblank_start, so incrementing crtc_vblank_start
> +		 * by 1 if both are equal.
> +		 */
> +		if (DISPLAY_VER(i915) >= 13 && crtc_state->has_panel_replay &&
> +		    adjusted_mode.crtc_vblank_start == adjusted_mode.crtc_vdisplay)
> +			adjusted_mode.crtc_vblank_start += 1;

Wrong place. It needs to done during compute_config/etc.

> +
>  		vmax_vblank_start = intel_vrr_vmax_vblank_start(crtc_state);
>  	} else {
>  		mode_flags &= ~I915_MODE_FLAG_VRR;
> -- 
> 2.29.0

-- 
Ville Syrjälä
Intel