linux-kernel - [PATCH v3 21/22] drm/bridge: imx8qxp-pixel-link: imx8qxp_pixel_link_find_next_bridge: return int, not ERR

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Message-Id: <20251216-drm-bridge-alloc-getput-drm_of_find_bridge-v3-21-b5165fab8058@bootlin.com>
Date: Tue, 16 Dec 2025 18:58:54 +0100
From: Luca Ceresoli <luca.ceresoli@...tlin.com>
To: Andrzej Hajda <andrzej.hajda@...el.com>, 
 Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
 Laurent Pinchart <Laurent.pinchart@...asonboard.com>, 
 Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Jonathan Corbet <corbet@....net>, Alexey Brodkin <abrodkin@...opsys.com>, 
 Phong LE <ple@...libre.com>, Liu Ying <victor.liu@....com>, 
 Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, Kevin Hilman <khilman@...libre.com>, 
 Jerome Brunet <jbrunet@...libre.com>, 
 Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Cc: Hui Pu <Hui.Pu@...ealthcare.com>, 
 Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
 linux-doc@...r.kernel.org, imx@...ts.linux.dev, 
 linux-arm-kernel@...ts.infradead.org, linux-amlogic@...ts.infradead.org, 
 Luca Ceresoli <luca.ceresoli@...tlin.com>
Subject: [PATCH v3 21/22] drm/bridge: imx8qxp-pixel-link:
 imx8qxp_pixel_link_find_next_bridge: return int, not ERR_PTR

In preparation for using bridge->next_bridge, we need to ensure that it
will never contain anything but NULL or a valid bridge pointer. Current
code stores an ERR_PTR when imx8qxp_pixel_link_find_next_bridge() errors
out. Instead of fixing that after the facts in the caller, change the
function to internally set pl->next_bridge and just return an int error
value.

No functional changes.

Signed-off-by: Luca Ceresoli <luca.ceresoli@...tlin.com>
---
 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
index 0c5ed06eee1b..91e4f4d55469 100644
--- a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
@@ -256,8 +256,7 @@ static int imx8qxp_pixel_link_disable_all_controls(struct imx8qxp_pixel_link *pl
 	return imx8qxp_pixel_link_disable_sync(pl);
 }
 
-static struct drm_bridge *
-imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
+static int imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 {
 	struct device_node *np = pl->dev->of_node;
 	struct device_node *port;
@@ -282,7 +281,7 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 
 	if (!found_port) {
 		DRM_DEV_ERROR(pl->dev, "no available output port\n");
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 	}
 
 	for (reg = 0; reg < PL_MAX_NEXT_BRIDGES; reg++) {
@@ -300,7 +299,7 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 
 		struct drm_bridge *next_bridge = of_drm_find_bridge(remote);
 		if (!next_bridge)
-			return ERR_PTR(-EPROBE_DEFER);
+			return -EPROBE_DEFER;
 
 		/*
 		 * Select the next bridge with companion PXL2DPI if
@@ -311,8 +310,9 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 	}
 
 	pl->mst_addr = port_id - 1;
+	pl->next_bridge = selected_bridge;
 
-	return selected_bridge;
+	return 0;
 }
 
 static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)
@@ -368,9 +368,9 @@ static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	pl->next_bridge = imx8qxp_pixel_link_find_next_bridge(pl);
-	if (IS_ERR(pl->next_bridge))
-		return PTR_ERR(pl->next_bridge);
+	ret = imx8qxp_pixel_link_find_next_bridge(pl);
+	if (ret)
+		return ret;
 
 	platform_set_drvdata(pdev, pl);
 

-- 
2.52.0