[Intel-gfx] [PATCH v4 18/18] drm/i915: Fix vblank evasion with vrr

[Manasi Navare]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

With vrr enabled the hardware no longer latches the registers
automagically at vblank start. The point at which it will do the
latching even when no push has been sent is the vmax decision
boundary. That is the thing we need to evade to avoid our
register latching to get split between two frames.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
---
 drivers/gpu/drm/i915/display/intel_sprite.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
index 0e82d1629d2d..530ce0497559 100644
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -101,7 +101,10 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
 	if (new_crtc_state->uapi.async_flip)
 		return;
 
-	vblank_start = intel_mode_vblank_start(adjusted_mode);
+	if (new_crtc_state->vrr.enable)
+		vblank_start = intel_vrr_vmax_vblank_start(new_crtc_state);
+	else
+		vblank_start = intel_mode_vblank_start(adjusted_mode);
 
 	/* FIXME needs to be calibrated sensibly */
 	min = vblank_start - intel_usecs_to_scanlines(adjusted_mode,
-- 
2.19.1