[PATCH] drm: rcar-du: Make sure DRM planes are created by VSP1

[Jacopo Mondi]

On Gen3 platforms compositing planes are allocated  by VSP on behalf of
DRM/KMS.
If VSP support is not compiled in, vsp1 initialization stub routine is
called, leading to invalid memory accesses later on when un-initialized
planes are accessed.

Fail explicitly earlier if planes are not properly created.

Signed-off-by: Jacopo Mondi <jacopo+renesas at jmondi.org>
---
 drivers/gpu/drm/rcar-du/rcar_du_kms.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index b5d3f16..7f56c09 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -616,6 +616,9 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 			ret = rcar_du_vsp_init(vsp);
 			if (ret < 0)
 				return ret;
+
+			if (!vsp->planes)
+				return -EINVAL;
 		}
 	}
 
-- 
2.7.4