[PATCH 4/4] drm/i915/vrr/xe2lpd: Use VRR timing generator whenever panel supports VRR

[Ankit Nautiyal]

Currently VRR timing generator is used only when VRR is enabled by
userspace. From XE2LPD, gradually move away from older timing
generator and use VRR timing generator if panel supports VRR but
VRR is not enabled by the userspace.
In such a case, Flipline VMin and VMax all are set to the Vtotal of the
mode, which effectively makes the VRR timing generator work in
fixed refresh rate mode. The same is conveyed to the sink via AS SDP,
by setting the Adaptive Sync Operation mode to AVT with fixed
video frame duration.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c  |  7 ++--
 drivers/gpu/drm/i915/display/intel_vrr.c | 45 +++++++++++++++---------
 2 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index b3c6623e0df3..dc162f271d78 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2627,6 +2627,7 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
 	struct drm_dp_as_sdp *as_sdp = &crtc_state->infoframes.as_sdp;
 	const struct drm_display_mode *adjusted_mode =
 		&crtc_state->hw.adjusted_mode;
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 
 	if (!crtc_state->vrr.enable ||
 	    !intel_dp_as_sdp_supported(intel_dp))
@@ -2634,10 +2635,12 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
 
 	crtc_state->infoframes.enable |= intel_hdmi_infoframe_enable(DP_SDP_ADAPTIVE_SYNC);
 
-	/* Currently only DP_AS_SDP_AVT_DYNAMIC_VTOTAL mode supported */
 	as_sdp->sdp_type = DP_SDP_ADAPTIVE_SYNC;
 	as_sdp->length = 0x9;
-	as_sdp->mode = DP_AS_SDP_AVT_DYNAMIC_VTOTAL;
+	if (crtc_state->uapi.vrr_enabled)
+		as_sdp->mode = DP_AS_SDP_AVT_DYNAMIC_VTOTAL;
+	else if (DISPLAY_VER(i915) >= 20)
+		as_sdp->mode = DP_AS_SDP_AVT_FIXED_VTOTAL;
 	as_sdp->vtotal = adjusted_mode->vtotal;
 	as_sdp->target_rr = 0;
 	as_sdp->duration_incr_ms = 0;
diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
index cdb2c224647c..4922c2540026 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -137,26 +137,37 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
 	if (HAS_LRR(i915))
 		crtc_state->update_lrr = true;
 
-	vmin = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000,
-			    adjusted_mode->crtc_htotal * info->monitor_range.max_vfreq);
-	vmax = adjusted_mode->crtc_clock * 1000 /
-		(adjusted_mode->crtc_htotal * info->monitor_range.min_vfreq);
+	if (!crtc_state->uapi.vrr_enabled && DISPLAY_VER(i915) >= 20) {
+		/*
+		 * for LNL+ if panel supports VRR and user has not set VRR,
+		 * always go for fixed average Vtotal mode.
+		 */
+		crtc_state->vrr.vmin = adjusted_mode->crtc_vtotal;
+		crtc_state->vrr.vmax = adjusted_mode->crtc_vtotal;
+		crtc_state->vrr.flipline = adjusted_mode->crtc_vtotal;
+	} else {
 
-	vmin = max_t(int, vmin, adjusted_mode->crtc_vtotal);
-	vmax = max_t(int, vmax, adjusted_mode->crtc_vtotal);
+		vmin = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000,
+				    adjusted_mode->crtc_htotal * info->monitor_range.max_vfreq);
+		vmax = adjusted_mode->crtc_clock * 1000 /
+			(adjusted_mode->crtc_htotal * info->monitor_range.min_vfreq);
 
-	if (vmin >= vmax)
-		return;
+		vmin = max_t(int, vmin, adjusted_mode->crtc_vtotal);
+		vmax = max_t(int, vmax, adjusted_mode->crtc_vtotal);
 
-	/*
-	 * flipline determines the min vblank length the hardware will
-	 * generate, and flipline>=vmin+1, hence we reduce vmin by one
-	 * to make sure we can get the actual min vblank length.
-	 */
-	crtc_state->vrr.vmin = vmin - 1;
-	crtc_state->vrr.vmax = vmax;
+		if (vmin >= vmax)
+			return;
+
+		/*
+		 * flipline determines the min vblank length the hardware will
+		 * generate, and flipline>=vmin+1, hence we reduce vmin by one
+		 * to make sure we can get the actual min vblank length.
+		 */
+		crtc_state->vrr.vmin = vmin - 1;
+		crtc_state->vrr.vmax = vmax;
 
-	crtc_state->vrr.flipline = crtc_state->vrr.vmin + 1;
+		crtc_state->vrr.flipline = crtc_state->vrr.vmin + 1;
+	}
 
 	/*
 	 * For XE_LPD+, we use guardband and pipeline override
@@ -171,7 +182,7 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
 			    crtc_state->framestart_delay - 1);
 	}
 
-	if (crtc_state->uapi.vrr_enabled) {
+	if (crtc_state->uapi.vrr_enabled || DISPLAY_VER(i915) >= 20) {
 		crtc_state->vrr.enable = true;
 		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
 		if (intel_dp_as_sdp_supported(intel_dp)) {
-- 
2.40.1