drm/imx: Use DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET flag

The IPUv3 display controller behind imx-drm needs all planes of
a CRTC be disabled when the CRTC is disabled.
The DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET flag reflects this
hardware requirement.  Let's use the flag for imx-drm.
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Liu Ying <gnuiyl@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/imx/imx-drm-core.c

@@ -194,7 +194,8 @@ static void imx_drm_atomic_commit_tail(struct drm_atomic_state *state)
 	drm_atomic_helper_commit_modeset_disables(dev, state);
 
 	drm_atomic_helper_commit_planes(dev, state,
-					DRM_PLANE_COMMIT_ACTIVE_ONLY);
+				DRM_PLANE_COMMIT_ACTIVE_ONLY |
+				DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET);
 
 	drm_atomic_helper_commit_modeset_enables(dev, state);
 

drivers/gpu/drm/imx/ipuv3-crtc.c

@@ -76,6 +76,9 @@ static void ipu_crtc_atomic_disable(struct drm_crtc *crtc,
 		crtc->state->event = NULL;
 	}
 	spin_unlock_irq(&crtc->dev->event_lock);
+
+	/* always disable planes on the CRTC */
+	drm_atomic_helper_disable_planes_on_crtc(old_crtc_state, true);
 }
 
 static void imx_drm_crtc_reset(struct drm_crtc *crtc)

drivers/gpu/drm/imx/ipuv3-plane.c

@@ -392,9 +392,13 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 	enum ipu_color_space ics;
 
 	if (old_state->fb) {
+		struct drm_crtc_state *crtc_state = state->crtc->state;
+
+		if (!drm_atomic_crtc_needs_modeset(crtc_state)) {
 			ipu_plane_atomic_set_base(ipu_plane, old_state);
 			return;
 		}
+	}
 
 	switch (ipu_plane->dp_flow) {
 	case IPU_DP_FLOW_SYNC_BG: