linux-kernel - [PATCH v3 15/22] drm/bridge: imx8qxp-pxl2dpi: imx8qxp_pxl2dpi_find_next_bridge: return int, not ERR

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Message-Id: <20251216-drm-bridge-alloc-getput-drm_of_find_bridge-v3-15-b5165fab8058@bootlin.com>
Date: Tue, 16 Dec 2025 18:58:48 +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 15/22] drm/bridge: imx8qxp-pxl2dpi:
 imx8qxp_pxl2dpi_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_pxl2dpi_find_next_bridge() errors
out. Instead of fixing that after the facts in the caller, change the
function to internally set the next_pointer 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-pxl2dpi.c | 30 +++++++++++-----------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c
index e03a411cb9db..2e66b003386e 100644
--- a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c
@@ -255,33 +255,27 @@ imx8qxp_pxl2dpi_get_available_ep_from_port(struct imx8qxp_pxl2dpi *p2d,
 	return ep;
 }
 
-static struct drm_bridge *
-imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d)
+static int imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d)
 {
-	struct drm_bridge *next_bridge;
-	int ret;
-
 	struct device_node *ep __free(device_node) =
 		imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1);
-	if (IS_ERR(ep)) {
-		ret = PTR_ERR(ep);
-		return ERR_PTR(ret);
-	}
+	if (IS_ERR(ep))
+		return PTR_ERR(ep);
 
 	struct device_node *remote __free(device_node) = of_graph_get_remote_port_parent(ep);
 	if (!remote || !of_device_is_available(remote)) {
 		DRM_DEV_ERROR(p2d->dev, "no available remote\n");
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 	} else if (!of_device_is_available(remote->parent)) {
 		DRM_DEV_ERROR(p2d->dev, "remote parent is not available\n");
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 	}
 
-	next_bridge = of_drm_find_bridge(remote);
-	if (!next_bridge)
-		return ERR_PTR(-EPROBE_DEFER);
+	p2d->next_bridge = of_drm_find_bridge(remote);
+	if (!p2d->next_bridge)
+		return -EPROBE_DEFER;
 
-	return next_bridge;
+	return 0;
 }
 
 static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d)
@@ -414,9 +408,9 @@ static int imx8qxp_pxl2dpi_bridge_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	p2d->next_bridge = imx8qxp_pxl2dpi_find_next_bridge(p2d);
-	if (IS_ERR(p2d->next_bridge))
-		return PTR_ERR(p2d->next_bridge);
+	ret = imx8qxp_pxl2dpi_find_next_bridge(p2d);
+	if (ret)
+		return ret;
 
 	ret = imx8qxp_pxl2dpi_set_pixel_link_sel(p2d);
 	if (ret)

-- 
2.52.0