drm: rcar-du: Use DRM-managed allocation for VSP planes

devm_kcalloc() is the wrong API to allocate planes, as the lifetime of
the planes is tied to the DRM device, not the device to driver
binding. drmm_kcalloc() isn't a good option either, as it would result
in the planes being freed before being unregistered during the managed
cleanup of the DRM objects. Use a plain kcalloc(), and cleanup the
planes and free the memory in the existing rcar_du_vsp_cleanup()
handler.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

drivers/gpu/drm/rcar-du/rcar_du_vsp.c

@@ -21,6 +21,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/of_platform.h>
 #include <linux/scatterlist.h>
+#include <linux/slab.h>
 #include <linux/videodev2.h>
 
 #include <media/vsp1.h>
@@ -344,6 +345,15 @@ static const struct drm_plane_funcs rcar_du_vsp_plane_funcs = {
 static void rcar_du_vsp_cleanup(struct drm_device *dev, void *res)
 {
 	struct rcar_du_vsp *vsp = res;
+	unsigned int i;
+
+	for (i = 0; i < vsp->num_planes; ++i) {
+		struct rcar_du_vsp_plane *plane = &vsp->planes[i];
+
+		drm_plane_cleanup(&plane->plane);
+	}
+
+	kfree(vsp->planes);
 
 	put_device(vsp->vsp);
 }
@@ -354,6 +364,7 @@ int rcar_du_vsp_init(struct rcar_du_vsp *vsp, struct device_node *np,
 	struct rcar_du_device *rcdu = vsp->dev;
 	struct platform_device *pdev;
 	unsigned int num_crtcs = hweight32(crtcs);
+	unsigned int num_planes;
 	unsigned int i;
 	int ret;
 
@@ -376,14 +387,13 @@ int rcar_du_vsp_init(struct rcar_du_vsp *vsp, struct device_node *np,
 	  * The VSP2D (Gen3) has 5 RPFs, but the VSP1D (Gen2) is limited to
 	  * 4 RPFs.
 	  */
-	vsp->num_planes = rcdu->info->gen >= 3 ? 5 : 4;
+	num_planes = rcdu->info->gen >= 3 ? 5 : 4;
 
-	vsp->planes = devm_kcalloc(rcdu->dev, vsp->num_planes,
-				   sizeof(*vsp->planes), GFP_KERNEL);
+	vsp->planes = kcalloc(num_planes, sizeof(*vsp->planes), GFP_KERNEL);
 	if (!vsp->planes)
 		return -ENOMEM;
 
-	for (i = 0; i < vsp->num_planes; ++i) {
+	for (i = 0; i < num_planes; ++i) {
 		enum drm_plane_type type = i < num_crtcs
 					 ? DRM_PLANE_TYPE_PRIMARY
 					 : DRM_PLANE_TYPE_OVERLAY;
@@ -409,8 +419,10 @@ int rcar_du_vsp_init(struct rcar_du_vsp *vsp, struct device_node *np,
 		} else {
 			drm_plane_create_alpha_property(&plane->plane);
 			drm_plane_create_zpos_property(&plane->plane, 1, 1,
-						       vsp->num_planes - 1);
+						       num_planes - 1);
 		}
+
+		vsp->num_planes++;
 	}
 
 	return 0;