[PATCH 12/13] drm/i915/vrr: Use crtc_vtotal for vmin

[Ankit Nautiyal]

To have fixed refresh rate with VRR timing generator the
guardband/pipeline full cant be programmed on the fly. So we need to
ensure that the values satisfy both the fixed and variable refresh
rates.

Since we compute these value based on vmin, lets set the vmin to
crtc_vtotal for both fixed and variable timings instead of using the
current refresh rate based approach. This way the guardband remains
sufficient for both cases.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_vrr.c | 34 +++++++++++++++++-------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
index 160d1b965bf3..5874aa76d626 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -246,18 +246,34 @@ void intel_vrr_compute_vrr_timings(struct intel_crtc_state *crtc_state)
 	crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
 }
 
+/*
+ * For fixed refresh rate mode Vmin, Vmax and Flipline all are set to
+ * Vtotal value.
+ */
 static
-int intel_vrr_compute_vmin(struct intel_connector *connector,
-			   struct drm_display_mode *adjusted_mode)
+int intel_vrr_fixed_rr_vtotal(const struct intel_crtc_state *crtc_state)
 {
-	int vmin;
-	const struct drm_display_info *info = &connector->base.display_info;
+	struct intel_display *display = to_intel_display(crtc_state);
+	int crtc_vtotal = crtc_state->hw.adjusted_mode.crtc_vtotal;
 
-	vmin = DIV_ROUND_UP(adjusted_mode->crtc_clock * 1000,
-			    adjusted_mode->crtc_htotal * info->monitor_range.max_vfreq);
-	vmin = max_t(int, vmin, adjusted_mode->crtc_vtotal);
+	if (DISPLAY_VER(display) >= 13)
+		return crtc_vtotal;
+	else
+		return crtc_vtotal -
+			intel_vrr_real_vblank_delay(crtc_state);
+}
 
-	return vmin;
+static
+int intel_vrr_compute_vmin(struct intel_crtc_state *crtc_state)
+{
+	/*
+	 * To make fixed rr and vrr work seamless the guardband/pipeline full
+	 * should be set such that it satisfies both the fixed and variable
+	 * timings.
+	 * For this set the vmin as crtc_vtotal. With this we never need to
+	 * change anything to do with the guardband.
+	 */
+	return intel_vrr_fixed_rr_vtotal(crtc_state);
 }
 
 static
@@ -310,7 +326,7 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
 	if (HAS_LRR(display))
 		crtc_state->update_lrr = true;
 
-	vmin = intel_vrr_compute_vmin(connector, adjusted_mode);
+	vmin = intel_vrr_compute_vmin(crtc_state);
 	vmax = intel_vrr_compute_vmax(connector, adjusted_mode);
 
 	if (vmin >= vmax)
-- 
2.45.2