[PATCH] drm/mediatek: Fix OVL iommu fault in cursor plane

[Jason-JH.Lin]

1. Accordin to the comment in drm_atomic_helper_async_commit(),
   we should make sure FBs have been swapped, so that cleanups in the
   new_state performs a cleanup in the old FB.
   So we should move swap_fb() to mtk_plane_update_new_state() done,
   to avoid using the old FB which could be freed.

2. OVL layer should not be enabled before crtc is enabled.
   The plane_state of drm_atomic_state is not sync to
   the plane_state stored in mtk_crtc during crtc enabling,
   so just set all planes to disabled.

Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
Fixes: 1a64a7aff8da ("drm/mediatek: Fix cursor plane no update")
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c  | 5 +++--
 drivers/gpu/drm/mediatek/mtk_drm_plane.c | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index d40142842f85..b3c631303a35 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -405,11 +405,12 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
 	/* Initially configure all planes */
 	for (i = 0; i < mtk_crtc->layer_nr; i++) {
 		struct drm_plane *plane = &mtk_crtc->planes[i];
-		struct mtk_plane_state *plane_state;
+		struct mtk_plane_state *plane_state = to_mtk_plane_state(plane->state);
 		struct mtk_ddp_comp *comp;
 		unsigned int local_layer;
 
-		plane_state = to_mtk_plane_state(plane->state);
+		/* should not enable layer before crtc enabled */
+		plane_state->pending.enable = false;
 		comp = mtk_drm_ddp_comp_for_plane(crtc, plane, &local_layer);
 		if (comp)
 			mtk_ddp_comp_layer_config(comp, local_layer,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index 31f9420aff6f..b1a918ffe457 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -210,9 +210,9 @@ static void mtk_plane_atomic_async_update(struct drm_plane *plane,
 	plane->state->src_y = new_state->src_y;
 	plane->state->src_h = new_state->src_h;
 	plane->state->src_w = new_state->src_w;
-	swap(plane->state->fb, new_state->fb);
 
 	mtk_plane_update_new_state(new_state, new_plane_state);
+	swap(plane->state->fb, new_state->fb);
 	wmb(); /* Make sure the above parameters are set before update */
 	new_plane_state->pending.async_dirty = true;
 	mtk_drm_crtc_async_update(new_state->crtc, plane, state);
-- 
2.18.0