[PATCH 7/8] drm/i915/display: Add vblank_start adjustment logic for always-on VRR TG

[Ankit Nautiyal <ankit.k.nautiyal@intel.com>]

As we move towards using a shorter, optimized guardband, we need to adjust
how the delayed vblank start is computed.

Adjust the crtc_vblank_start using Vmin Vtotal - guardband only when
intel_vrr_always_use_vrr_tg() is true.

This also paves way for guardband optimization, by handling the movement of
the crtc_vblank_start for platforms that have VRR TG always active.

v2: Drop the helper and add the adjustment directly to
intel_vrr_compute_guardband(). Ville

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
---
 drivers/gpu/drm/i915/display/intel_vrr.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
index 221b25832e56..5f9b8e5c48be 100644
--- a/drivers/gpu/drm/i915/display/intel_vrr.c
+++ b/drivers/gpu/drm/i915/display/intel_vrr.c
@@ -436,7 +436,7 @@ intel_vrr_max_guardband(struct intel_crtc_state *crtc_state)
 void intel_vrr_compute_guardband(struct intel_crtc_state *crtc_state)
 {
 	struct intel_display *display = to_intel_display(crtc_state);
-	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
+	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
 
 	if (!intel_vrr_possible(crtc_state))
 		return;
@@ -444,6 +444,10 @@ void intel_vrr_compute_guardband(struct intel_crtc_state *crtc_state)
 	crtc_state->vrr.guardband = min(crtc_state->vrr.vmin - adjusted_mode->crtc_vdisplay,
 					intel_vrr_max_guardband(crtc_state));
 
+	if (intel_vrr_always_use_vrr_tg(display))
+		adjusted_mode->crtc_vblank_start  =
+			crtc_state->vrr.vmin - crtc_state->vrr.guardband;
+
 	if (DISPLAY_VER(display) < 13)
 		crtc_state->vrr.pipeline_full =
 			intel_vrr_guardband_to_pipeline_full(crtc_state,
-- 
2.45.2