linux-kernel - [PATCH 6/6] drm/omap: dss: convert to of_drm_find_and_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20260116-drm-bridge-alloc-getput-drm_of_find_bridge-4-v1-6-e34b38f50d27@bootlin.com>
Date: Fri, 16 Jan 2026 18:32:41 +0100
From: Luca Ceresoli <luca.ceresoli@...tlin.com>
To: Biju Das <biju.das.jz@...renesas.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>, 
 Anitha Chrisanthus <anitha.chrisanthus@...el.com>, 
 Edmund Dea <edmund.j.dea@...el.com>, Linus Walleij <linusw@...nel.org>, 
 Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>, 
 Tomi Valkeinen <tomi.valkeinen+renesas@...asonboard.com>, 
 Kieran Bingham <kieran.bingham+renesas@...asonboard.com>, 
 Geert Uytterhoeven <geert+renesas@...der.be>, 
 Magnus Damm <magnus.damm@...il.com>, 
 Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Cc: Hui Pu <Hui.Pu@...ealthcare.com>, Ian Ray <ian.ray@...ealthcare.com>, 
 Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 dri-devel@...ts.freedesktop.org, linux-renesas-soc@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Luca Ceresoli <luca.ceresoli@...tlin.com>
Subject: [PATCH 6/6] drm/omap: dss: convert to of_drm_find_and_get_bridge()

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

omapdss_device_init_output() can take one bridge pointer in out->bridge or
two pointers in out->bridge and out->next_bridge. Ensure each has a
corresponding drm_bridge_get() and add drm_bridge_put() calls in the
cleanup code.

Also slightly change the initial code assigning out->panel and out->bridge
to ensure and clarify that either out->panel or out->bridge is set in the
function prologue, not both. If both were set, the 'if (out->panel){...}'
code that follows would overwrite out->bridge without having put the
reference.

Finally, take a reference in case a panel_bridge is added using
drm_panel_bridge_add(). This ensures we always need to put a reference,
which came either from of_drm_find_and_get_bridge() or by the
drm_panel_bridge_add+drm_bridge_get() branch.

Signed-off-by: Luca Ceresoli <luca.ceresoli@...tlin.com>
---
 drivers/gpu/drm/omapdrm/dss/output.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/output.c b/drivers/gpu/drm/omapdrm/dss/output.c
index 7378e855c278..ca891aba3820 100644
--- a/drivers/gpu/drm/omapdrm/dss/output.c
+++ b/drivers/gpu/drm/omapdrm/dss/output.c
@@ -30,11 +30,13 @@ int omapdss_device_init_output(struct omap_dss_device *out,
 		return 0;
 	}
 
-	out->bridge = of_drm_find_bridge(remote_node);
 	out->panel = of_drm_find_panel(remote_node);
 	if (IS_ERR(out->panel))
 		out->panel = NULL;
 
+	if (!out->panel)
+		out->bridge = of_drm_find_and_get_bridge(remote_node);
+
 	of_node_put(remote_node);
 
 	if (out->panel) {
@@ -49,7 +51,7 @@ int omapdss_device_init_output(struct omap_dss_device *out,
 			goto error;
 		}
 
-		out->bridge = bridge;
+		out->bridge = drm_bridge_get(bridge);
 	}
 
 	if (local_bridge) {
@@ -59,7 +61,7 @@ int omapdss_device_init_output(struct omap_dss_device *out,
 		}
 
 		out->next_bridge = out->bridge;
-		out->bridge = local_bridge;
+		out->bridge = drm_bridge_get(local_bridge);
 	}
 
 	if (!out->bridge) {
@@ -79,6 +81,9 @@ void omapdss_device_cleanup_output(struct omap_dss_device *out)
 	if (out->bridge && out->panel)
 		drm_panel_bridge_remove(out->next_bridge ?
 					out->next_bridge : out->bridge);
+
+	drm_bridge_put(out->next_bridge);
+	drm_bridge_put(out->bridge);
 }
 
 void dss_mgr_set_timings(struct omap_dss_device *dssdev,

-- 
2.52.0