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

[Animesh Manna]

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