drm/imx: switch to universal planes

Use drm_universal_plane_init to create the planes, create the primary
plane first and use drm_crtc_init_with_planes to associate it with
the crtc.
This gets rid of the unused fallback primary plane previously created
by drm_crtc_init and fixes a NULL pointer dereference issue that can
be triggered by a modeset from userspace when fbdev helpers are
enabled [1].

[1] https://lkml.org/lkml/2015/11/4/107Reported-by: Liu Ying <Ying.Liu@freescale.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Liu Ying <Ying.Liu@freescale.com>

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

@@ -340,7 +340,7 @@ static int imx_drm_driver_load(struct drm_device *drm, unsigned long flags)
  * imx_drm_add_crtc - add a new crtc
  */
 int imx_drm_add_crtc(struct drm_device *drm, struct drm_crtc *crtc,
-		struct imx_drm_crtc **new_crtc,
+		struct imx_drm_crtc **new_crtc, struct drm_plane *primary_plane,
 		const struct imx_drm_crtc_helper_funcs *imx_drm_helper_funcs,
 		struct device_node *port)
 {
@@ -379,7 +379,7 @@ int imx_drm_add_crtc(struct drm_device *drm, struct drm_crtc *crtc,
 	drm_crtc_helper_add(crtc,
 			imx_drm_crtc->imx_drm_helper_funcs.crtc_helper_funcs);
 
-	drm_crtc_init(drm, crtc,
+	drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
 			imx_drm_crtc->imx_drm_helper_funcs.crtc_funcs);
 
 	return 0;

drivers/gpu/drm/imx/imx-drm.h

@@ -9,6 +9,7 @@ struct drm_display_mode;
 struct drm_encoder;
 struct drm_fbdev_cma;
 struct drm_framebuffer;
+struct drm_plane;
 struct imx_drm_crtc;
 struct platform_device;
 
@@ -24,7 +25,7 @@ struct imx_drm_crtc_helper_funcs {
 };
 
 int imx_drm_add_crtc(struct drm_device *drm, struct drm_crtc *crtc,
-		struct imx_drm_crtc **new_crtc,
+		struct imx_drm_crtc **new_crtc, struct drm_plane *primary_plane,
 		const struct imx_drm_crtc_helper_funcs *imx_helper_funcs,
 		struct device_node *port);
 int imx_drm_remove_crtc(struct imx_drm_crtc *);

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

@@ -349,7 +349,6 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
 	struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);
 	int dp = -EINVAL;
 	int ret;
-	int id;
 
 	ret = ipu_get_resources(ipu_crtc, pdata);
 	if (ret) {
@@ -358,18 +357,19 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
 		return ret;
 	}
 
+	if (pdata->dp >= 0)
+		dp = IPU_DP_FLOW_SYNC_BG;
+	ipu_crtc->plane[0] = ipu_plane_init(drm, ipu, pdata->dma[0], dp, 0,
+					    DRM_PLANE_TYPE_PRIMARY);
+
 	ret = imx_drm_add_crtc(drm, &ipu_crtc->base, &ipu_crtc->imx_crtc,
-			&ipu_crtc_helper_funcs, ipu_crtc->dev->of_node);
+			&ipu_crtc->plane[0]->base, &ipu_crtc_helper_funcs,
+			ipu_crtc->dev->of_node);
 	if (ret) {
 		dev_err(ipu_crtc->dev, "adding crtc failed with %d.\n", ret);
 		goto err_put_resources;
 	}
 
-	if (pdata->dp >= 0)
-		dp = IPU_DP_FLOW_SYNC_BG;
-	id = imx_drm_crtc_id(ipu_crtc->imx_crtc);
-	ipu_crtc->plane[0] = ipu_plane_init(ipu_crtc->base.dev, ipu,
-					    pdata->dma[0], dp, BIT(id), true);
 	ret = ipu_plane_get_resources(ipu_crtc->plane[0]);
 	if (ret) {
 		dev_err(ipu_crtc->dev, "getting plane 0 resources failed with %d.\n",
@@ -379,10 +379,10 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
 
 	/* If this crtc is using the DP, add an overlay plane */
 	if (pdata->dp >= 0 && pdata->dma[1] > 0) {
-		ipu_crtc->plane[1] = ipu_plane_init(ipu_crtc->base.dev, ipu,
-						    pdata->dma[1],
+		ipu_crtc->plane[1] = ipu_plane_init(drm, ipu, pdata->dma[1],
 						IPU_DP_FLOW_SYNC_FG,
-						    BIT(id), false);
+						drm_crtc_mask(&ipu_crtc->base),
+						DRM_PLANE_TYPE_OVERLAY);
 		if (IS_ERR(ipu_crtc->plane[1]))
 			ipu_crtc->plane[1] = NULL;
 	}

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

@@ -381,7 +381,7 @@ static struct drm_plane_funcs ipu_plane_funcs = {
 
 struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
 				 int dma, int dp, unsigned int possible_crtcs,
-				 bool priv)
+				 enum drm_plane_type type)
 {
 	struct ipu_plane *ipu_plane;
 	int ret;
@@ -399,10 +399,9 @@ struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
 	ipu_plane->dma = dma;
 	ipu_plane->dp_flow = dp;
 
-	ret = drm_plane_init(dev, &ipu_plane->base, possible_crtcs,
+	ret = drm_universal_plane_init(dev, &ipu_plane->base, possible_crtcs,
 				       &ipu_plane_funcs, ipu_plane_formats,
-			     ARRAY_SIZE(ipu_plane_formats),
-			     priv);
+				       ARRAY_SIZE(ipu_plane_formats), type);
 	if (ret) {
 		DRM_ERROR("failed to initialize plane\n");
 		kfree(ipu_plane);

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

@@ -34,7 +34,7 @@ struct ipu_plane {
 
 struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
 				 int dma, int dp, unsigned int possible_crtcs,
-				 bool priv);
+				 enum drm_plane_type type);
 
 /* Init IDMAC, DMFC, DP */
 int ipu_plane_mode_set(struct ipu_plane *plane, struct drm_crtc *crtc,