linux-kernel - [PATCH v2 3/6] drm/mcde: dsi: mcde_dsi_bind: break when a panel or bridge is found

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Message-Id: <20260131-drm-bridge-alloc-getput-drm_of_find_bridge-4-v2-3-e081bcdc1467@bootlin.com>
Date: Sat, 31 Jan 2026 16:58:35 +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>, 
 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 v2 3/6] drm/mcde: dsi: mcde_dsi_bind: break when a panel or
 bridge is found

mcde_dsi_bind() has a loop over all subnodes looking for a panel, but does
not exit when a match is found and only stores the last match. However this
will be problematic when introducing refcounting on the struct drm_device
pointer in a following commit, because of_drm_find_and_get_bridge() would
get a reference to multiple bridges.

There seem to be no real reason for looking for multiple panels, so just
break as soon as a match is found.

Signed-off-by: Luca Ceresoli <luca.ceresoli@...tlin.com>

---

Changes in v2:
- break instead of warning as suggested by Linus Walleij:
  https://lore.kernel.org/r/CAD++jLm_Va+7c_usgoPDhsDiCr4NQMZWsQ3iJW5-a1ETP4EaJQ@mail.gmail.com
---
 drivers/gpu/drm/mcde/mcde_dsi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c
index a3423459dd7a..5893fd2681b3 100644
--- a/drivers/gpu/drm/mcde/mcde_dsi.c
+++ b/drivers/gpu/drm/mcde/mcde_dsi.c
@@ -1116,6 +1116,11 @@ static int mcde_dsi_bind(struct device *dev, struct device *master,
 				return -EINVAL;
 			}
 		}
+
+		if (panel || bridge) {
+			of_node_put(child);
+			break;
+		}
 	}
 	if (panel) {
 		bridge = drm_panel_bridge_add_typed(panel,

-- 
2.52.0