if (!rcrtc->started)
return;
+ /* Disable all planes and wait for the change to take effect. This is
+ * required as the DSnPR registers are updated on vblank, and no vblank
+ * will occur once the CRTC is stopped. Disabling planes when starting
+ * the CRTC thus wouldn't be enough as it would start scanning out
+ * immediately from old frame buffers until the next vblank.
+ *
+ * This increases the CRTC stop delay, especially when multiple CRTCs
+ * are stopped in one operation as we now wait for one vblank per CRTC.
+ * Whether this can be improved needs to be researched.
+ */
+ rcar_du_group_write(rcrtc->group, rcrtc->index % 2 ? DS2PR : DS1PR, 0);
+ drm_crtc_wait_one_vblank(crtc);
+
/* Disable vertical blanking interrupt reporting. We first need to wait
* for page flip completion before stopping the CRTC as userspace
* expects page flips to eventually complete.