drm/i915: Disable VRR during seamless M/N changes

Make life less confusing by making sure VRR is disabled whenever
we do any drastic changes to the display timings, such as seamless
M/N changes.

Cc: Manasi Navare <navaremanasi@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230901130440.2085-10-ville.syrjala@linux.intel.comReviewed-by: Manasi Navare <navaremanasi@chromium.org>
Reviewed-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>

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

@@ -916,13 +916,15 @@ static bool planes_disabling(const struct intel_crtc_state *old_crtc_state,
 static bool vrr_enabling(const struct intel_crtc_state *old_crtc_state,
 			 const struct intel_crtc_state *new_crtc_state)
 {
-	return is_enabling(vrr.enable, old_crtc_state, new_crtc_state);
+	return is_enabling(vrr.enable, old_crtc_state, new_crtc_state) ||
+		(new_crtc_state->vrr.enable && new_crtc_state->update_m_n);
 }
 
 static bool vrr_disabling(const struct intel_crtc_state *old_crtc_state,
 			  const struct intel_crtc_state *new_crtc_state)
 {
-	return is_disabling(vrr.enable, old_crtc_state, new_crtc_state);
+	return is_disabling(vrr.enable, old_crtc_state, new_crtc_state) ||
+		(old_crtc_state->vrr.enable && new_crtc_state->update_m_n);
 }
 
 #undef is_disabling