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([2001:250:5800:1000::f280]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-83965d38ab5sm10162541b3a.26.2026.05.07.03.08.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2026 03:08:45 -0700 (PDT) From: Guangshuo Li To: Liu Ying , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Frank Li , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Luca Ceresoli , dri-devel@lists.freedesktop.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Guangshuo Li , stable@vger.kernel.org Subject: [PATCH v7] drm/bridge: imx8qxp-pxl2dpi: avoid ERR_PTR with device_node cleanup Date: Thu, 7 May 2026 18:06:03 +0800 Message-ID: <20260507100604.667731-1-lgs201920130244@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: ceea3f7806a10 ("drm/bridge: imx8qxp-pxl2dpi: simplify put of device_node pointers") Cc: stable@vger.kernel.org Reviewed-by: Liu Ying Signed-off-by: Guangshuo Li --- v7: - Rephrase the commit message sentence about output argument initialization as suggested by Liu Ying. - Drop the unnecessary sentence about keeping explicit of_node_put() usage. - Add Liu Ying's Reviewed-by tag. - No code changes. v6: - Change imx8qxp_pxl2dpi_get_available_ep_from_port() to return int and pass the endpoint through an output argument. - Keep using __free(device_node) in imx8qxp_pxl2dpi_find_next_bridge(). - Keep ep initialized to NULL in imx8qxp_pxl2dpi_find_next_bridge() to satisfy the __free pointer initialization requirement. - Do not add cleanup action usage in imx8qxp_pxl2dpi_get_available_ep_from_port() or imx8qxp_pxl2dpi_set_pixel_link_sel(). v5: - Make the fix minimal for stable by avoiding __free(device_node) for the endpoint node in imx8qxp_pxl2dpi_find_next_bridge(). - Keep imx8qxp_pxl2dpi_get_available_ep_from_port() unchanged. - Do not change imx8qxp_pxl2dpi_set_pixel_link_sel(). - Drop Frank's Reviewed-by tag due to the implementation change. 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 | 40 +++++++++++--------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c index 441fd32dc91c..d64e328bf542 100644 --- a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c @@ -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) { -- 2.43.0