[Intel-gfx] [PATCH 11/12] drm/i915: Assert that VRR is off during vblank evasion if necessary

[Ville Syrjala]

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

Whenever we change the actual transcoder timings (clock via
seamless M/N, full modeset, (or soon) vtotal via LRR) we
want the timing generator to be in non-VRR during the commit.
Warn if we forgot to turn VRR off prior to vblank evasion.

Cc: Manasi Navare <navaremanasi at chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_crtc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index a04076064f02..a39e31c1ca85 100644
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -493,6 +493,10 @@ static void intel_crtc_vblank_evade_scanlines(struct intel_atomic_state *state,
 	adjusted_mode = &crtc_state->hw.adjusted_mode;
 
 	if (crtc->mode_flags & I915_MODE_FLAG_VRR) {
+		/* timing changes should happen with VRR disabled */
+		drm_WARN_ON(state->base.dev, intel_crtc_needs_modeset(new_crtc_state) ||
+			    new_crtc_state->update_m_n);
+
 		if (intel_vrr_is_push_sent(crtc_state))
 			*vblank_start = intel_vrr_vmin_vblank_start(crtc_state);
 		else
-- 
2.41.0