drm/i915/vrr: Introduce intel_vrr_vblank_delay()

Introduce a VRR specific function for determining the current
vblank delay. Currently thus will give the same answer as
intel_mode_vblank_delay() but that will change later.

Signed-off-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Ankit Nautiyal <[email protected]>

Author: vsyrjala

drivers/gpu/drm/i915/display/intel_dsb.c

@@ -109,9 +109,16 @@ static bool pre_commit_is_vrr_active(struct intel_atomic_state *state,
 	return old_crtc_state->vrr.enable && !intel_crtc_vrr_disabling(state, crtc);
 }
 
-static int dsb_vblank_delay(const struct intel_crtc_state *crtc_state)
+static int dsb_vblank_delay(struct intel_atomic_state *state,
+			    struct intel_crtc *crtc)
 {
-	return intel_mode_vblank_delay(&crtc_state->hw.adjusted_mode);
+	const struct intel_crtc_state *crtc_state =
+		intel_pre_commit_crtc_state(state, crtc);
+
+	if (pre_commit_is_vrr_active(state, crtc))
+		return intel_vrr_vblank_delay(crtc_state);
+	else
+		return intel_mode_vblank_delay(&crtc_state->hw.adjusted_mode);
 }
 
 static int dsb_vtotal(struct intel_atomic_state *state,
@@ -520,10 +527,11 @@ void intel_dsb_vblank_evade(struct intel_atomic_state *state,
 		intel_pre_commit_crtc_state(state, crtc);
 	/* FIXME calibrate sensibly */
 	int latency = intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode, 20);
-	int vblank_delay = dsb_vblank_delay(crtc_state);
 	int start, end;
 
 	if (pre_commit_is_vrr_active(state, crtc)) {
+		int vblank_delay = intel_vrr_vblank_delay(crtc_state);
+
 		end = intel_vrr_vmin_vblank_start(crtc_state);
 		start = end - vblank_delay - latency;
 		intel_dsb_wait_scanline_out(state, dsb, start, end);
@@ -532,6 +540,8 @@ void intel_dsb_vblank_evade(struct intel_atomic_state *state,
 		start = end - vblank_delay - latency;
 		intel_dsb_wait_scanline_out(state, dsb, start, end);
 	} else {
+		int vblank_delay = intel_mode_vblank_delay(&crtc_state->hw.adjusted_mode);
+
 		end = intel_mode_vblank_start(&crtc_state->hw.adjusted_mode);
 		start = end - vblank_delay - latency;
 		intel_dsb_wait_scanline_out(state, dsb, start, end);
@@ -612,7 +622,7 @@ void intel_dsb_wait_vblank_delay(struct intel_atomic_state *state,
 	const struct intel_crtc_state *crtc_state =
 		intel_pre_commit_crtc_state(state, crtc);
 	int usecs = intel_scanlines_to_usecs(&crtc_state->hw.adjusted_mode,
-					     dsb_vblank_delay(crtc_state)) + 1;
+					     dsb_vblank_delay(state, crtc)) + 1;
 
 	intel_dsb_wait_usec(dsb, usecs);
 }

drivers/gpu/drm/i915/display/intel_vblank.c

@@ -641,6 +641,7 @@ void intel_vblank_evade_init(const struct intel_crtc_state *old_crtc_state,
 	struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->uapi.crtc);
 	const struct intel_crtc_state *crtc_state;
 	const struct drm_display_mode *adjusted_mode;
+	int vblank_delay;
 
 	evade->crtc = crtc;
 
@@ -662,8 +663,12 @@ void intel_vblank_evade_init(const struct intel_crtc_state *old_crtc_state,
 			evade->vblank_start = intel_vrr_vmin_vblank_start(crtc_state);
 		else
 			evade->vblank_start = intel_vrr_vmax_vblank_start(crtc_state);
+
+		vblank_delay = intel_vrr_vblank_delay(crtc_state);
 	} else {
 		evade->vblank_start = intel_mode_vblank_start(adjusted_mode);
+
+		vblank_delay = intel_mode_vblank_delay(adjusted_mode);
 	}
 
 	/* FIXME needs to be calibrated sensibly */
@@ -681,7 +686,7 @@ void intel_vblank_evade_init(const struct intel_crtc_state *old_crtc_state,
 	 */
 	if (intel_color_uses_dsb(new_crtc_state) ||
 	    new_crtc_state->update_m_n || new_crtc_state->update_lrr)
-		evade->min -= intel_mode_vblank_delay(adjusted_mode);
+		evade->min -= vblank_delay;
 }
 
 /* must be called with vblank interrupt already enabled! */

drivers/gpu/drm/i915/display/intel_vrr.c

@@ -75,6 +75,12 @@ intel_vrr_check_modeset(struct intel_atomic_state *state)
 	}
 }
 
+int intel_vrr_vblank_delay(const struct intel_crtc_state *crtc_state)
+{
+	return crtc_state->hw.adjusted_mode.crtc_vblank_start -
+		crtc_state->hw.adjusted_mode.crtc_vdisplay;
+}
+
 /*
  * Without VRR registers get latched at:
  *  vblank_start

drivers/gpu/drm/i915/display/intel_vrr.h

@@ -30,5 +30,6 @@ int intel_vrr_vmax_vtotal(const struct intel_crtc_state *crtc_state);
 int intel_vrr_vmin_vtotal(const struct intel_crtc_state *crtc_state);
 int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state);
 int intel_vrr_vmin_vblank_start(const struct intel_crtc_state *crtc_state);
+int intel_vrr_vblank_delay(const struct intel_crtc_state *crtc_state);
 
 #endif /* __INTEL_VRR_H__ */