drm: mxsfb: Move vblank event arm to CRTC .atomic_flush()

The vblank event is armed in the plane .atomic_update(). This works fine
as we have a single plane, and was the only option when the driver was
using the drm_simple_kms_helper helper, but will break as soon as
multiple planes are supported. Move it to CRTC .atomic_flush().
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200727020654.8231-13-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/mxsfb/mxsfb_kms.c

@@ -295,6 +295,25 @@ static int mxsfb_crtc_atomic_check(struct drm_crtc *crtc,
 	return drm_atomic_add_affected_planes(state->state, crtc);
 }
 
+static void mxsfb_crtc_atomic_flush(struct drm_crtc *crtc,
+				    struct drm_crtc_state *old_state)
+{
+	struct drm_pending_vblank_event *event;
+
+	event = crtc->state->event;
+	crtc->state->event = NULL;
+
+	if (!event)
+		return;
+
+	spin_lock_irq(&crtc->dev->event_lock);
+	if (drm_crtc_vblank_get(crtc) == 0)
+		drm_crtc_arm_vblank_event(crtc, event);
+	else
+		drm_crtc_send_vblank_event(crtc, event);
+	spin_unlock_irq(&crtc->dev->event_lock);
+}
+
 static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc,
 				     struct drm_crtc_state *old_state)
 {
@@ -364,6 +383,7 @@ static void mxsfb_crtc_disable_vblank(struct drm_crtc *crtc)
 
 static const struct drm_crtc_helper_funcs mxsfb_crtc_helper_funcs = {
 	.atomic_check = mxsfb_crtc_atomic_check,
+	.atomic_flush = mxsfb_crtc_atomic_flush,
 	.atomic_enable = mxsfb_crtc_atomic_enable,
 	.atomic_disable = mxsfb_crtc_atomic_disable,
 };
@@ -410,23 +430,8 @@ static void mxsfb_plane_atomic_update(struct drm_plane *plane,
 				      struct drm_plane_state *old_pstate)
 {
 	struct mxsfb_drm_private *mxsfb = to_mxsfb_drm_private(plane->dev);
-	struct drm_crtc *crtc = &mxsfb->crtc;
-	struct drm_pending_vblank_event *event;
 	dma_addr_t paddr;
 
-	spin_lock_irq(&crtc->dev->event_lock);
-	event = crtc->state->event;
-	if (event) {
-		crtc->state->event = NULL;
-
-		if (drm_crtc_vblank_get(crtc) == 0) {
-			drm_crtc_arm_vblank_event(crtc, event);
-		} else {
-			drm_crtc_send_vblank_event(crtc, event);
-		}
-	}
-	spin_unlock_irq(&crtc->dev->event_lock);
-
 	paddr = mxsfb_get_fb_paddr(mxsfb);
 	if (paddr) {
 		mxsfb_enable_axi_clk(mxsfb);