[PATCH] drm: mxsfb: fix fence synchronization

[Lucas Stach]

The conversion away from the simple display pipeline helper missed
to convert the prepare_fb plane callback, so no fences are attached to
the atomic state, breaking synchronization with other devices. Fix
this by plugging in the drm_gem_fb_prepare_fb helper function.

Fixes: ae1ed009328 (drm: mxsfb: Stop using DRM simple display pipeline helper)
Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 drivers/gpu/drm/mxsfb/mxsfb_kms.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index b721b8b262ce..4d556532281a 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
@@ -22,6 +22,7 @@
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane.h>
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_vblank.h>
@@ -485,11 +486,13 @@ static void mxsfb_plane_overlay_atomic_update(struct drm_plane *plane,
 }
 
 static const struct drm_plane_helper_funcs mxsfb_plane_primary_helper_funcs = {
+	.prepare_fb = drm_gem_fb_prepare_fb,
 	.atomic_check = mxsfb_plane_atomic_check,
 	.atomic_update = mxsfb_plane_primary_atomic_update,
 };
 
 static const struct drm_plane_helper_funcs mxsfb_plane_overlay_helper_funcs = {
+	.prepare_fb = drm_gem_fb_prepare_fb,
 	.atomic_check = mxsfb_plane_atomic_check,
 	.atomic_update = mxsfb_plane_overlay_atomic_update,
 };
-- 
2.20.1