drm/panel: of_drm_find_panel() return a counted reference

Callers of of_drm_find_panel() and drm_of_find_panel_or_bridge()
receive a pointer with no reference held, creating a window where
the panel device can be unregistered and freed between the lookup
and first use (e.g., drm_panel_prepare()).

Fix the lookup function by acquiring a reference with drm_panel_get()
before returning, under panel_lock. Callers are now responsible for
calling drm_panel_put() when they no longer need the pointer.

For bridge drivers that immediately wrap the panel in a panel_bridge
(which acquires its own reference), release the lookup reference right
after the bridge creation call.

For analogix-anx6345, which stores the panel for direct use, release
the reference in the i2c remove path.

For platform drivers using analogix_dp_core with a component lifecycle
(exynos_dp, rockchip analogix_dp), release the lookup reference in the
platform remove() function. The panel_bridge created during bind() holds
a separate reference that devm cleanup releases after remove() returns.

Also fix devm_drm_of_get_bridge() and drmm_of_get_bridge() in
bridge/panel.c itself, update a second batch of drivers calling
of_drm_find_panel() or drm_of_find_panel_or_bridge() to release the
lookup reference after wrapping the panel in a bridge, and handle the
cases where a panel is found but cannot be used, dropping the reference
immediately in those paths.

Assisted-by: Claude:claude-opus-4-6
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260717-drm_refcount_wiring-v3-3-023900c32e01@redhat.com

drivers/gpu/drm/bridge/analogix/analogix-anx6345.c

@@ -663,6 +663,11 @@ static bool anx6345_get_chip_id(struct anx6345 *anx6345)
 	return false;
 }
 
+static void anx6345_panel_put_action(void *data)
+{
+	drm_panel_put(data);
+}
+
 static int anx6345_i2c_probe(struct i2c_client *client)
 {
 	struct anx6345 *anx6345;
@@ -691,6 +696,13 @@ static int anx6345_i2c_probe(struct i2c_client *client)
 	if (err)
 		DRM_DEBUG("No panel found\n");
 
+	if (anx6345->panel) {
+		err = devm_add_action_or_reset(dev, anx6345_panel_put_action,
+					       anx6345->panel);
+		if (err)
+			return err;
+	}
+
 	/* 1.2V digital core power regulator  */
 	anx6345->dvdd12 = devm_regulator_get(dev, "dvdd12");
 	if (IS_ERR(anx6345->dvdd12)) {

drivers/gpu/drm/bridge/fsl-ldb.c

@@ -348,6 +348,7 @@ static int fsl_ldb_probe(struct platform_device *pdev)
 		fsl_ldb->use_termination_resistor = true;
 
 	fsl_ldb->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+	drm_panel_put(panel);
 	if (IS_ERR(fsl_ldb->panel_bridge))
 		return PTR_ERR(fsl_ldb->panel_bridge);
 

drivers/gpu/drm/bridge/lontium-lt9211.c

@@ -660,6 +660,7 @@ static int lt9211_parse_dt(struct lt9211 *ctx)
 		return ret;
 	if (panel) {
 		panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+		drm_panel_put(panel);
 		if (IS_ERR(panel_bridge))
 			return PTR_ERR(panel_bridge);
 	}

drivers/gpu/drm/bridge/lvds-codec.c

@@ -156,6 +156,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
 	lvds_codec->panel_bridge =
 		devm_drm_panel_bridge_add_typed(dev, panel,
 						lvds_codec->connector_type);
+	drm_panel_put(panel);
 	if (IS_ERR(lvds_codec->panel_bridge))
 		return PTR_ERR(lvds_codec->panel_bridge);
 

drivers/gpu/drm/bridge/panel.c

@@ -515,8 +515,10 @@ struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
 	if (ret)
 		return ERR_PTR(ret);
 
-	if (panel)
+	if (panel) {
 		bridge = devm_drm_panel_bridge_add(dev, panel);
+		drm_panel_put(panel);
+	}
 
 	return bridge;
 }
@@ -549,8 +551,10 @@ struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
 	if (ret)
 		return ERR_PTR(ret);
 
-	if (panel)
+	if (panel) {
 		bridge = drmm_panel_bridge_add(drm, panel);
+		drm_panel_put(panel);
+	}
 
 	return bridge;
 }

drivers/gpu/drm/bridge/samsung-dsim.c

@@ -1934,6 +1934,7 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
 	panel = of_drm_find_panel(remote);
 	if (!IS_ERR(panel)) {
 		next_bridge = devm_drm_panel_bridge_add(dev, panel);
+		drm_panel_put(panel);
 		if (IS_ERR(next_bridge)) {
 			ret = PTR_ERR(next_bridge);
 			next_bridge = NULL; // Inhibit the cleanup action on an ERR_PTR

drivers/gpu/drm/bridge/ssd2825.c

@@ -301,6 +301,7 @@ static int ssd2825_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_d
 
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel, DRM_MODE_CONNECTOR_DSI);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
 	}

drivers/gpu/drm/bridge/tc358767.c

@@ -2329,6 +2329,7 @@ static int tc_probe_dpi_bridge_endpoint(struct tc_data *tc)
 
 	if (panel) {
 		bridge = devm_drm_panel_bridge_add(dev, panel);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
 	}
@@ -2359,6 +2360,7 @@ static int tc_probe_edp_bridge_endpoint(struct tc_data *tc)
 		struct drm_bridge *panel_bridge;
 
 		panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+		drm_panel_put(panel);
 		if (IS_ERR(panel_bridge))
 			return PTR_ERR(panel_bridge);
 

drivers/gpu/drm/bridge/tc358768.c

@@ -479,6 +479,7 @@ static int tc358768_dsi_host_attach(struct mipi_dsi_host *host,
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel,
 						    DRM_MODE_CONNECTOR_DSI);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
 

drivers/gpu/drm/bridge/waveshare-dsi.c

@@ -169,6 +169,7 @@ static int ws_bridge_probe(struct i2c_client *i2c)
 		return dev_err_probe(dev, ret, "Failed to find remote panel\n");
 
 	ws->next_bridge = devm_drm_panel_bridge_add(dev, panel);
+	drm_panel_put(panel);
 	if (IS_ERR(ws->next_bridge))
 		return PTR_ERR(ws->next_bridge);
 

drivers/gpu/drm/drm_of.c

@@ -269,7 +269,8 @@ EXPORT_SYMBOL_GPL(drm_of_get_panel_orientation);
  * @np: device tree node containing encoder output ports
  * @port: port in the device tree node
  * @endpoint: endpoint in the device tree node
- * @panel: pointer to hold returned drm_panel, must not be NULL
+ * @panel: pointer to hold returned drm_panel, must not be NULL. On success
+ *         the caller must call drm_panel_put() when done with the panel
  * @bridge: pointer to hold returned drm_bridge
  *
  * Given a DT node's port and endpoint number, find the connected node and

drivers/gpu/drm/drm_panel.c

@@ -459,14 +459,17 @@ EXPORT_SYMBOL(__devm_drm_panel_alloc);
 
 #ifdef CONFIG_OF
 /**
- * of_drm_find_panel - look up a panel using a device tree node
+ * of_drm_find_panel - look up and reference a panel by device tree node
  * @np: device tree node of the panel
  *
  * Searches the set of registered panels for one that matches the given device
- * tree node. If a matching panel is found, return a pointer to it.
+ * tree node. If a matching panel is found, the panel's reference count is
+ * incremented before returning a pointer to it. The caller must call
+ * drm_panel_put() when it no longer needs the panel pointer.
  *
- * Return: A pointer to the panel registered for the specified device tree
+ * Return: A reference-counted pointer to the panel registered for the specified
- * node or an ERR_PTR() if no panel matching the device tree node can be found.
+ * device tree node or an ERR_PTR() if no panel matching the device tree node
+ * can be found.
  *
  * Possible error codes returned by this function:
  *
@@ -485,6 +488,7 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
 
 	list_for_each_entry(panel, &panel_list, list) {
 		if (panel->dev->of_node == np) {
+			drm_panel_get(panel);
 			mutex_unlock(&panel_lock);
 			return panel;
 		}

drivers/gpu/drm/exynos/exynos_dp.c

@@ -182,8 +182,15 @@ static int exynos_dp_probe(struct platform_device *pdev)
 
 out:
 	dp->adp = analogix_dp_probe(dev, &dp->plat_data);
-	if (IS_ERR(dp->adp))
+	if (IS_ERR(dp->adp)) {
+		/*
+		 * The driver core does not invoke remove() for failed probes,
+		 * so release the probe-time panel reference here.
+		 */
+		if (dp->plat_data.panel)
+			drm_panel_put(dp->plat_data.panel);
 		return PTR_ERR(dp->adp);
+	}
 
 	if (dp->plat_data.panel || dp->plat_data.next_bridge)
 		return component_add(&pdev->dev, &exynos_dp_ops);
@@ -193,6 +200,16 @@ static int exynos_dp_probe(struct platform_device *pdev)
 
 static void exynos_dp_remove(struct platform_device *pdev)
 {
+	struct exynos_dp_device *dp = platform_get_drvdata(pdev);
+
+	/*
+	 * Release the probe-time reference from of_drm_find_panel(). If bind
+	 * ran, the panel_bridge holds a second reference that devm cleanup
+	 * will release when the bridge is destroyed after remove() returns.
+	 */
+	if (dp->plat_data.panel)
+		drm_panel_put(dp->plat_data.panel);
+
 	component_del(&pdev->dev, &exynos_dp_ops);
 }
 

drivers/gpu/drm/exynos/exynos_drm_dpi.c

@@ -245,5 +245,8 @@ int exynos_dpi_remove(struct drm_encoder *encoder)
 
 	exynos_dpi_disable(&ctx->encoder);
 
+	if (ctx->panel)
+		drm_panel_put(ctx->panel);
+
 	return 0;
 }

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c

@@ -109,6 +109,13 @@ static int fsl_dcu_attach_panel(struct fsl_dcu_drm_device *fsl_dev,
 	return ret;
 }
 
+static void fsl_dcu_panel_put_action(void *data)
+{
+	struct drm_panel *panel = data;
+
+	drm_panel_put(panel);
+}
+
 int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev)
 {
 	struct device_node *panel_node;
@@ -124,6 +131,12 @@ int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev)
 		if (IS_ERR(fsl_dev->connector.panel))
 			return PTR_ERR(fsl_dev->connector.panel);
 
+		ret = devm_add_action_or_reset(fsl_dev->dev,
+					       fsl_dcu_panel_put_action,
+					       fsl_dev->connector.panel);
+		if (ret)
+			return ret;
+
 		return fsl_dcu_attach_panel(fsl_dev, fsl_dev->connector.panel);
 	}
 
@@ -132,6 +145,11 @@ int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev)
 		return ret;
 
 	if (panel) {
+		ret = devm_add_action_or_reset(fsl_dev->dev,
+					       fsl_dcu_panel_put_action, panel);
+		if (ret)
+			return ret;
+
 		fsl_dev->connector.panel = panel;
 		return fsl_dcu_attach_panel(fsl_dev, panel);
 	}

drivers/gpu/drm/imx/dcss/dcss-kms.c

@@ -77,6 +77,9 @@ static int dcss_kms_bridge_connector_init(struct dcss_kms_dev *kms)
 	if (ret)
 		return ret;
 
+	if (panel)
+		drm_panel_put(panel);
+
 	if (!bridge) {
 		dev_err(ddev->dev, "No bridge found %d.\n", ret);
 		return -ENODEV;

drivers/gpu/drm/ingenic/ingenic-drm-drv.c

@@ -1297,9 +1297,11 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
 			goto err_drvdata;
 		}
 
-		if (panel)
+		if (panel) {
 			bridge = devm_drm_panel_bridge_add_typed(dev, panel,
 								 DRM_MODE_CONNECTOR_DPI);
+			drm_panel_put(panel);
+		}
 
 		ib = drmm_encoder_alloc(drm, struct ingenic_drm_bridge, encoder,
 					NULL, DRM_MODE_ENCODER_DPI, NULL);

drivers/gpu/drm/logicvc/logicvc_interface.c

@@ -28,6 +28,11 @@
 #define logicvc_interface_from_drm_connector(c) \
 	container_of(c, struct logicvc_interface, drm_connector)
 
+static void logicvc_panel_put_action(void *data)
+{
+	drm_panel_put(data);
+}
+
 static void logicvc_encoder_enable(struct drm_encoder *drm_encoder)
 {
 	struct logicvc_drm *logicvc = logicvc_drm(drm_encoder->dev);
@@ -160,6 +165,13 @@ int logicvc_interface_init(struct logicvc_drm *logicvc)
 	if (ret == -EPROBE_DEFER)
 		goto error_early;
 
+	if (interface->drm_panel) {
+		ret = devm_add_action_or_reset(dev, logicvc_panel_put_action,
+					       interface->drm_panel);
+		if (ret)
+			goto error_early;
+	}
+
 	ret = drm_encoder_init(drm_dev, &interface->drm_encoder,
 			       &logicvc_encoder_funcs, encoder_type, NULL);
 	if (ret) {

drivers/gpu/drm/mcde/mcde_drv.c

@@ -153,6 +153,7 @@ static int mcde_modeset_init(struct drm_device *drm)
 		if (panel) {
 			bridge = drm_panel_bridge_add_typed(panel,
 					DRM_MODE_CONNECTOR_DPI);
+			drm_panel_put(panel);
 			if (IS_ERR(bridge)) {
 				dev_err(drm->dev,
 					"Could not connect panel bridge\n");

drivers/gpu/drm/mcde/mcde_dsi.c

@@ -1127,6 +1127,7 @@ static int mcde_dsi_bind(struct device *dev, struct device *master,
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel,
 						    DRM_MODE_CONNECTOR_DSI);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge)) {
 			dev_err(dev, "error adding panel bridge\n");
 			return PTR_ERR(bridge);

drivers/gpu/drm/mxsfb/mxsfb_drv.c

@@ -127,6 +127,7 @@ static int mxsfb_attach_bridge(struct mxsfb_drm_private *mxsfb)
 	if (panel) {
 		bridge = devm_drm_panel_bridge_add_typed(drm->dev, panel,
 							 DRM_MODE_CONNECTOR_DPI);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
 	}

drivers/gpu/drm/omapdrm/dss/output.c

@@ -43,6 +43,7 @@ int omapdss_device_init_output(struct omap_dss_device *out,
 		struct drm_bridge *bridge;
 
 		bridge = drm_panel_bridge_add(out->panel);
+		drm_panel_put(out->panel);
 		if (IS_ERR(bridge)) {
 			dev_err(out->dev,
 				"unable to create panel bridge (%ld)\n",

drivers/gpu/drm/pl111/pl111_drv.c

@@ -145,6 +145,7 @@ static int pl111_modeset_init(struct drm_device *dev)
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel,
 						    DRM_MODE_CONNECTOR_Unknown);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto finish;

drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c

@@ -69,6 +69,7 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
 
 		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
 							 DRM_MODE_CONNECTOR_DPI);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return PTR_ERR(no_free_ptr(bridge));
 

drivers/gpu/drm/renesas/rcar-du/rcar_lvds.c

@@ -791,6 +791,7 @@ static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
 	if (lvds->panel) {
 		lvds->next_bridge = devm_drm_panel_bridge_add(lvds->dev,
 							      lvds->panel);
+		drm_panel_put(lvds->panel);
 		if (IS_ERR_OR_NULL(lvds->next_bridge)) {
 			ret = -EINVAL;
 			goto done;

drivers/gpu/drm/renesas/rz-du/rzg2l_du_encoder.c

@@ -90,6 +90,7 @@ int rzg2l_du_encoder_init(struct rzg2l_du_device  *rcdu,
 
 		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
 							 DRM_MODE_CONNECTOR_DPI);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return PTR_ERR(no_free_ptr(bridge));
 

drivers/gpu/drm/rockchip/analogix_dp-rockchip.c

@@ -28,6 +28,7 @@
 #include <drm/drm_bridge_connector.h>
 #include <drm/bridge/analogix_dp.h>
 #include <drm/drm_of.h>
+#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 
@@ -485,6 +486,16 @@ static int rockchip_dp_probe(struct platform_device *pdev)
 
 static void rockchip_dp_remove(struct platform_device *pdev)
 {
+	struct rockchip_dp_device *dp = platform_get_drvdata(pdev);
+
+	/*
+	 * Release the probe-time reference from of_drm_find_panel(). If bind
+	 * ran, the panel_bridge holds a second reference that devm cleanup
+	 * will release when the bridge is destroyed after remove() returns.
+	 */
+	if (dp->plat_data.panel)
+		drm_panel_put(dp->plat_data.panel);
+
 	component_del(&pdev->dev, &rockchip_dp_component_ops);
 }
 

drivers/gpu/drm/rockchip/rockchip_lvds.c

@@ -610,6 +610,8 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master,
 
 	if (lvds->panel) {
 		lvds->bridge = drm_panel_bridge_add_typed(lvds->panel, DRM_MODE_CONNECTOR_LVDS);
+		drm_panel_put(lvds->panel);
+		lvds->panel = NULL;
 		if (IS_ERR(lvds->bridge)) {
 			ret = PTR_ERR(lvds->bridge);
 			goto err_free_encoder;
@@ -646,6 +648,8 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master,
 err_free_encoder:
 	drm_encoder_cleanup(encoder);
 err_put_remote:
+	if (lvds->panel)
+		drm_panel_put(lvds->panel);
 	of_node_put(remote);
 err_put_port:
 	of_node_put(port);

drivers/gpu/drm/rockchip/rockchip_rgb.c

@@ -135,6 +135,8 @@ struct rockchip_rgb *rockchip_rgb_init(struct device *dev,
 	if (ret < 0) {
 		DRM_DEV_ERROR(drm_dev->dev,
 			      "failed to initialize encoder: %d\n", ret);
+		if (panel)
+			drm_panel_put(panel);
 		return ERR_PTR(ret);
 	}
 
@@ -143,6 +145,7 @@ struct rockchip_rgb *rockchip_rgb_init(struct device *dev,
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel,
 						    DRM_MODE_CONNECTOR_LVDS);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge))
 			return ERR_CAST(bridge);
 	}

drivers/gpu/drm/sti/sti_dvo.c

@@ -498,6 +498,9 @@ static void sti_dvo_unbind(struct device *dev,
 {
 	struct sti_dvo *dvo = dev_get_drvdata(dev);
 
+	if (dvo->panel)
+		drm_panel_put(dvo->panel);
+
 	drm_bridge_remove(&dvo->bridge);
 }
 

drivers/gpu/drm/stm/ltdc.c

@@ -1982,6 +1982,7 @@ int ltdc_load(struct drm_device *ddev)
 
 		if (panel) {
 			bridge = drmm_panel_bridge_add(ddev, panel);
+			drm_panel_put(panel);
 			if (IS_ERR(bridge)) {
 				drm_err(ddev, "panel-bridge endpoint %d\n", i);
 				ret = PTR_ERR(bridge);

drivers/gpu/drm/stm/lvds.c

@@ -1068,20 +1068,20 @@ static int lvds_probe(struct platform_device *pdev)
 	if (IS_ERR(lvds->base)) {
 		ret = PTR_ERR(lvds->base);
 		dev_err(dev, "Unable to get regs %d\n", ret);
-		return ret;
+		goto err_put_panel;
 	}
 
 	lvds->pclk = devm_clk_get(dev, "pclk");
 	if (IS_ERR(lvds->pclk)) {
 		ret = PTR_ERR(lvds->pclk);
 		dev_err(dev, "Unable to get peripheral clock: %d\n", ret);
-		return ret;
+		goto err_put_panel;
 	}
 
 	ret = clk_prepare_enable(lvds->pclk);
 	if (ret) {
 		dev_err(dev, "%s: Failed to enable peripheral clk\n", __func__);
-		return ret;
+		goto err_put_panel;
 	}
 
 	rstc = devm_reset_control_get_exclusive(dev, NULL);
@@ -1181,6 +1181,9 @@ static int lvds_probe(struct platform_device *pdev)
 
 err_lvds_probe:
 	clk_disable_unprepare(lvds->pclk);
+err_put_panel:
+	if (lvds->panel)
+		drm_panel_put(lvds->panel);
 
 	return ret;
 }
@@ -1189,6 +1192,9 @@ static void lvds_remove(struct platform_device *pdev)
 {
 	struct stm_lvds *lvds = platform_get_drvdata(pdev);
 
+	if (lvds->panel)
+		drm_panel_put(lvds->panel);
+
 	lvds_pixel_clk_unregister(lvds);
 
 	drm_bridge_remove(&lvds->lvds_bridge);

drivers/gpu/drm/sun4i/sun4i_lvds.c

@@ -18,6 +18,11 @@
 #include "sun4i_tcon.h"
 #include "sun4i_lvds.h"
 
+static void sun4i_panel_put_action(void *data)
+{
+	drm_panel_put(data);
+}
+
 struct sun4i_lvds {
 	struct drm_connector	connector;
 	struct drm_encoder	encoder;
@@ -117,6 +122,14 @@ int sun4i_lvds_init(struct drm_device *drm, struct sun4i_tcon *tcon)
 		return 0;
 	}
 
+	if (lvds->panel) {
+		ret = devm_add_action_or_reset(tcon->dev,
+					       sun4i_panel_put_action,
+					       lvds->panel);
+		if (ret)
+			return ret;
+	}
+
 	drm_encoder_helper_add(&lvds->encoder,
 			       &sun4i_lvds_enc_helper_funcs);
 	ret = drm_encoder_init(drm, &lvds->encoder, &sun4i_lvds_enc_funcs,

drivers/gpu/drm/sun4i/sun4i_rgb.c

@@ -43,6 +43,11 @@ drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
 			    encoder);
 }
 
+static void sun4i_panel_put_action(void *data)
+{
+	drm_panel_put(data);
+}
+
 static int sun4i_rgb_get_modes(struct drm_connector *connector)
 {
 	struct sun4i_rgb *rgb =
@@ -209,6 +214,14 @@ int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
 		return 0;
 	}
 
+	if (rgb->panel) {
+		ret = devm_add_action_or_reset(tcon->dev,
+					       sun4i_panel_put_action,
+					       rgb->panel);
+		if (ret)
+			return ret;
+	}
+
 	drm_encoder_helper_add(&rgb->encoder,
 			       &sun4i_rgb_enc_helper_funcs);
 	ret = drm_encoder_init(drm, &rgb->encoder, &sun4i_rgb_enc_funcs,

drivers/gpu/drm/sun4i/sun4i_tcon.c

@@ -1326,6 +1326,8 @@ static int sun4i_tcon_probe(struct platform_device *pdev)
 		ret = drm_of_find_panel_or_bridge(node, 1, 0, &panel, &bridge);
 		if (ret == -EPROBE_DEFER)
 			return ret;
+		if (panel)
+			drm_panel_put(panel);
 	}
 
 	return component_add(&pdev->dev, &sun4i_tcon_ops);

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c

@@ -971,8 +971,10 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,
 
 	if (IS_ERR(panel))
 		return PTR_ERR(panel);
-	if (!dsi->drm || !dsi->drm->registered)
+	if (!dsi->drm || !dsi->drm->registered) {
+		drm_panel_put(panel);
 		return -EPROBE_DEFER;
+	}
 
 	dsi->panel = panel;
 	dsi->device = device;
@@ -989,6 +991,8 @@ static int sun6i_dsi_detach(struct mipi_dsi_host *host,
 {
 	struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);
 
+	if (dsi->panel)
+		drm_panel_put(dsi->panel);
 	dsi->panel = NULL;
 	dsi->device = NULL;
 

drivers/gpu/drm/tegra/dsi.c

@@ -1527,6 +1527,10 @@ static int tegra_dsi_host_attach(struct mipi_dsi_host *host,
 	if (!dsi->master) {
 		struct tegra_output *output = &dsi->output;
 
+		/*
+		 * tegra_output_probe() never populates a panel for DSI
+		 * outputs, so output->panel is always NULL here.
+		 */
 		output->panel = of_drm_find_panel(device->dev.of_node);
 		if (IS_ERR(output->panel))
 			output->panel = NULL;
@@ -1545,6 +1549,7 @@ static int tegra_dsi_host_detach(struct mipi_dsi_host *host,
 	struct tegra_output *output = &dsi->output;
 
 	if (output->panel && &device->dev == output->panel->dev) {
+		drm_panel_put(output->panel);
 		output->panel = NULL;
 
 		if (output->connector.dev)

drivers/gpu/drm/tegra/output.c

@@ -117,11 +117,19 @@ int tegra_output_probe(struct tegra_output *output)
 		 */
 		WARN_ON(output->panel || output->bridge);
 
+		if (output->panel) {
+			drm_panel_put(output->panel);
+			output->panel = NULL;
+		}
+
 		output->panel = of_drm_find_panel(panel);
 		of_node_put(panel);
 
-		if (IS_ERR(output->panel))
+		if (IS_ERR(output->panel)) {
-			return PTR_ERR(output->panel);
+			err = PTR_ERR(output->panel);
+			output->panel = NULL;
+			return err;
+		}
 	}
 
 	ddc = of_parse_phandle(output->of_node, "nvidia,ddc-i2c-bus", 0);
@@ -131,7 +139,7 @@ int tegra_output_probe(struct tegra_output *output)
 
 		if (!output->ddc) {
 			err = -EPROBE_DEFER;
-			return err;
+			goto put_i2c;
 		}
 	}
 
@@ -185,6 +193,11 @@ int tegra_output_probe(struct tegra_output *output)
 	return 0;
 
 put_i2c:
+	if (output->panel) {
+		drm_panel_put(output->panel);
+		output->panel = NULL;
+	}
+
 	if (output->ddc)
 		i2c_put_adapter(output->ddc);
 
@@ -195,6 +208,11 @@ int tegra_output_probe(struct tegra_output *output)
 
 void tegra_output_remove(struct tegra_output *output)
 {
+	if (output->panel) {
+		drm_panel_put(output->panel);
+		output->panel = NULL;
+	}
+
 	if (output->hpd_gpio)
 		free_irq(output->hpd_irq, output);
 

drivers/gpu/drm/tidss/tidss_kms.c

@@ -162,6 +162,7 @@ static int tidss_dispc_modeset_init(struct tidss_device *tidss)
 
 		if (panel) {
 			u32 conn_type;
+			int ret;
 
 			dev_dbg(dev, "Setting up panel for port %d\n", i);
 
@@ -176,7 +177,8 @@ static int tidss_dispc_modeset_init(struct tidss_device *tidss)
 				break;
 			default:
 				WARN_ON(1);
-				return -EINVAL;
+				ret = -EINVAL;
+				goto put_panel;
 			}
 
 			if (panel->connector_type != conn_type) {
@@ -184,16 +186,20 @@ static int tidss_dispc_modeset_init(struct tidss_device *tidss)
 					"%s: Panel %s has incompatible connector type for vp%d (%d != %d)\n",
 					 __func__, dev_name(panel->dev), i,
 					 panel->connector_type, conn_type);
-				return -EINVAL;
+				ret = -EINVAL;
+				goto put_panel;
 			}
 
 			bridge = devm_drm_panel_bridge_add(dev, panel);
-			if (IS_ERR(bridge)) {
+			ret = PTR_ERR_OR_ZERO(bridge);
+			if (ret)
 				dev_err(dev,
 					"failed to set up panel bridge for port %d\n",
 					i);
-				return PTR_ERR(bridge);
+put_panel:
-			}
+			drm_panel_put(panel);
+			if (ret)
+				return ret;
 		}
 
 		pipes[num_pipes].hw_videoport = i;

drivers/gpu/drm/tve200/tve200_drv.c

@@ -84,6 +84,7 @@ static int tve200_modeset_init(struct drm_device *dev)
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel,
 						    DRM_MODE_CONNECTOR_Unknown);
+		drm_panel_put(panel);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto out_bridge;