From: Luca Ceresoli <luca.ceresoli@bootlin.com>
Date: Mon, 11 May 2026 16:40:14 +0000 (+0200)
Subject: drm: zynqmp_dp: switch to of_drm_get_bridge_by_endpoint()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=62f1a79e1b004b250e68e10c32a29fd954fc9725;p=thirdparty%2Fkernel%2Flinux.git

drm: zynqmp_dp: switch to of_drm_get_bridge_by_endpoint()

This driver calls drm_of_find_panel_or_bridge() with a NULL pointer in the
@panel parameter, thus using a reduced feature set of that function.
Replace this call with the simpler of_drm_get_bridge_by_endpoint().

Since of_drm_get_bridge_by_endpoint() increases the refcount of the
returned bridge, ensure it is put on removal. To achieve this, instead of
adding an explicit drm_bridge_put(), migrate to the bridge::next_bridge
pointer which is automatically put when the bridge is eventually freed.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patch.msgid.link/20260511-drm-bridge-alloc-getput-panel_or_bridge-v6-10-f61c9e498b3f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 05bd31fe675bc..7fb11b0a44f0c 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -353,7 +353,6 @@ struct zynqmp_dp_train_set_priv {
  * @lock: Mutex protecting this struct and register access (but not AUX)
  * @irq: irq
  * @bridge: DRM bridge for the DP encoder
- * @next_bridge: The downstream bridge
  * @test: Configuration for test mode
  * @config: IP core configuration from DTS
  * @aux: aux channel
@@ -385,7 +384,6 @@ struct zynqmp_dp {
 	struct completion aux_done;
 	struct mutex lock;
 
-	struct drm_bridge *next_bridge;
 	struct device *dev;
 	struct zynqmp_dpsub *dpsub;
 	void __iomem *iomem;
@@ -1494,8 +1492,8 @@ static int zynqmp_dp_bridge_attach(struct drm_bridge *bridge,
 		return ret;
 	}
 
-	if (dp->next_bridge) {
-		ret = drm_bridge_attach(encoder, dp->next_bridge,
+	if (dp->bridge.next_bridge) {
+		ret = drm_bridge_attach(encoder, dp->bridge.next_bridge,
 					bridge, flags);
 		if (ret < 0)
 			goto error;
@@ -2461,10 +2459,15 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub)
 	 * Acquire the next bridge in the chain. Ignore errors caused by port@5
 	 * not being connected for backward-compatibility with older DTs.
 	 */
-	ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 5, 0, NULL,
-					  &dp->next_bridge);
-	if (ret < 0 && ret != -ENODEV)
-		goto err_reset;
+	dp->bridge.next_bridge = of_drm_get_bridge_by_endpoint(dp->dev->of_node, 5, 0);
+	if (IS_ERR(dp->bridge.next_bridge)) {
+		if (PTR_ERR(dp->bridge.next_bridge) != -ENODEV) {
+			ret = PTR_ERR(dp->bridge.next_bridge);
+			goto err_reset;
+		}
+
+		dp->bridge.next_bridge = NULL;
+	}
 
 	/* Initialize the hardware. */
 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;