Messages in this thread Patch in this message |  | | From | Guangshuo Li <> | | Subject | [PATCH v4] drm/bridge: imx8qxp-pxl2dpi: avoid ERR_PTR with device_node cleanup | | Date | Tue, 5 May 2026 16:21:45 +0800 |
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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. Return the error code from imx8qxp_pxl2dpi_get_available_ep_from_port() directly and pass the endpoint node through an output argument. This keeps the cleanup action operating only on NULL or a valid device_node, while preserving the existing error codes.
Fixes: ceea3f7806a10 ("drm/bridge: imx8qxp-pxl2dpi: simplify put of device_node pointers") Cc: stable@vger.kernel.org Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com> --- v4: - Drop the sentence mentioning the custom static analysis tool. - Add Frank's Reviewed-by tag. - No functional code changes.
v3: - Do not change DEFINE_FREE(device_node, ...). - Fix the driver pattern by making imx8qxp_pxl2dpi_get_available_ep_from_port() return an int and pass the endpoint via an output argument. - Update both callers so __free(device_node) never holds ERR_PTR().
v2: - Fix DEFINE_FREE(device_node, ...) directly.
drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c | 54 ++++++++++---------- 1 file changed, 26 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c index 441fd32dc91c..881ebb811eb3 100644 --- a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c @@ -222,52 +222,52 @@ 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 __free(device_node) = + of_graph_get_port_by_id(p2d->dev->of_node, port_id); int ep_cnt; - port = of_graph_get_port_by_id(p2d->dev->of_node, port_id); + *ep = NULL; 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); - goto out; + return -ENODEV; } else if (ep_cnt > 1) { DRM_DEV_ERROR(p2d->dev, "invalid available endpoints of port@%u\n", port_id); - ep = ERR_PTR(-EINVAL); - goto out; + return -EINVAL; } - 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); - goto out; + return -ENODEV; } -out: - of_node_put(port); - return ep; + + return 0; } 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)) { @@ -287,26 +287,24 @@ static int imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d) static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d) { - struct device_node *ep; + struct device_node *ep __free(device_node) = NULL; 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) { DRM_DEV_ERROR(p2d->dev, "failed to parse endpoint of port@0: %d\n", ret); - goto out; + return ret; } p2d->pl_sel = endpoint.id; -out: - of_node_put(ep); - return ret; + return 0; } static int imx8qxp_pxl2dpi_parse_dt_companion(struct imx8qxp_pxl2dpi *p2d) -- 2.43.0
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