Commit 53597dec authored by Guangshuo Li's avatar Guangshuo Li Committed by Liu Ying
Browse files

drm/bridge: imx8qxp-pxl2dpi: avoid ERR_PTR with device_node cleanup 



imx8qxp_pxl2dpi_get_available_ep_from_port() returns ERR_PTR()
on errors. imx8qxp_pxl2dpi_find_next_bridge() stores its return
value in a __free(device_node) variable before checking IS_ERR().
When the function returns on the error path, the cleanup action calls
of_node_put() on the ERR_PTR() value.

Do not let a device_node cleanup variable hold error pointers. Change
imx8qxp_pxl2dpi_get_available_ep_from_port() to return an int and pass
the endpoint node through an output argument. Initialize the output
argument to NULL so callers hold either NULL on error paths or a valid
device_node pointer on successful path.

Fixes: ceea3f78 ("drm/bridge: imx8qxp-pxl2dpi: simplify put of device_node pointers")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarLiu Ying <victor.liu@nxp.com>
Signed-off-by: default avatarGuangshuo Li <lgs201920130244@gmail.com>
Link: https://patch.msgid.link/20260507100604.667731-1-lgs201920130244@gmail.com


Signed-off-by: default avatarLiu Ying <victor.liu@nxp.com>
parent b2ed01e7

drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c

+23 −17
Original line number Diff line number Diff line
@@ -222,52 +222,58 @@ static const struct drm_bridge_funcs imx8qxp_pxl2dpi_bridge_funcs = { 
			imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts,

};



static struct device_node *

static int

imx8qxp_pxl2dpi_get_available_ep_from_port(struct imx8qxp_pxl2dpi *p2d,

					   u32 port_id)

					   u32 port_id,

					   struct device_node **ep)

{

	struct device_node *port, *ep;

	struct device_node *port;

	int ret = 0;

	int ep_cnt;



	*ep = NULL;



	port = of_graph_get_port_by_id(p2d->dev->of_node, port_id);

	if (!port) {

		DRM_DEV_ERROR(p2d->dev, "failed to get port@%u\n", port_id);

		return ERR_PTR(-ENODEV);

		return -ENODEV;

	}



	ep_cnt = of_get_available_child_count(port);

	if (ep_cnt == 0) {

		DRM_DEV_ERROR(p2d->dev, "no available endpoints of port@%u\n",

			      port_id);

		ep = ERR_PTR(-ENODEV);

		ret = -ENODEV;

		goto out;

	} else if (ep_cnt > 1) {

		DRM_DEV_ERROR(p2d->dev,

			      "invalid available endpoints of port@%u\n",

			      port_id);

		ep = ERR_PTR(-EINVAL);

		ret = -EINVAL;

		goto out;

	}



	ep = of_get_next_available_child(port, NULL);

	if (!ep) {

	*ep = of_get_next_available_child(port, NULL);

	if (!*ep) {

		DRM_DEV_ERROR(p2d->dev,

			      "failed to get available endpoint of port@%u\n",

			      port_id);

		ep = ERR_PTR(-ENODEV);

		ret = -ENODEV;

		goto out;

	}

out:

	of_node_put(port);

	return ep;

	return ret;

}



static int imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d)

{

	struct device_node *ep __free(device_node) =

		imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1);

	if (IS_ERR(ep))

		return PTR_ERR(ep);

	struct device_node *ep __free(device_node) = NULL;

	int ret;



	ret = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1, &ep);

	if (ret)

		return ret;



	struct device_node *remote __free(device_node) = of_graph_get_remote_port_parent(ep);

	if (!remote || !of_device_is_available(remote)) {
@@ -291,9 +297,9 @@ static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d) 
	struct of_endpoint endpoint;

	int ret;



	ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0);

	if (IS_ERR(ep))

		return PTR_ERR(ep);

	ret = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0, &ep);

	if (ret)

		return ret;



	ret = of_graph_parse_endpoint(ep, &endpoint);

	if (ret) {