linux-kernel - [PATCH v8 2/3] dmr/bridge: add a .destroy func

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Message-Id: <20250516-drm-bridge-alloc-doc-test-v8-2-7e356fd58ba5@bootlin.com>
Date: Fri, 16 May 2025 18:48:38 +0200
From: Luca Ceresoli <luca.ceresoli@...tlin.com>
To: 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>, 
 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>
Cc: Anusha Srivatsa <asrivats@...hat.com>, 
 Paul Kocialkowski <paulk@...-base.io>, Dmitry Baryshkov <lumag@...nel.org>, 
 Hervé Codina <herve.codina@...tlin.com>, 
 Hui Pu <Hui.Pu@...ealthcare.com>, 
 Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
 Luca Ceresoli <luca.ceresoli@...tlin.com>
Subject: [PATCH v8 2/3] dmr/bridge: add a .destroy func

Some users of DRM bridges may need to execute specific code just before
deallocation.

As of now the only known user would be KUnit tests.

Suggested-by: Maxime Ripard <mripard@...nel.org>
Signed-off-by: Luca Ceresoli <luca.ceresoli@...tlin.com>

---

This patch is new in v8. The .destroy callback had appeared in v5 as well
[5], but as part of a larger patch and for different reason that do not
apply anymore.

[5] https://lore.kernel.org/all/20241231-hotplug-drm-bridge-v5-3-173065a1ece1@bootlin.com/#t
---
 drivers/gpu/drm/drm_bridge.c |  2 ++
 include/drm/drm_bridge.h     | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index b4c89ec01998b849018ce031c7cd84614e65e710..6185cb29fe3162264f0912c09c205fb467975dee 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -203,6 +203,8 @@ static void __drm_bridge_free(struct kref *kref)
 {
 	struct drm_bridge *bridge = container_of(kref, struct drm_bridge, refcount);
 
+	if (bridge->funcs->destroy)
+		bridge->funcs->destroy(bridge);
 	kfree(bridge->container);
 }
 
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 4e418a29a9ff9d014d6ac0910a5d9bcf7118195e..3ccd493faa580845c2ed1166f398eca27b464261 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -86,6 +86,16 @@ struct drm_bridge_funcs {
 	 */
 	void (*detach)(struct drm_bridge *bridge);
 
+	/**
+	 * @destroy:
+	 *
+	 * This callback is invoked when the bridge is about to be
+	 * deallocated.
+	 *
+	 * The @destroy callback is optional.
+	 */
+	void (*destroy)(struct drm_bridge *bridge);
+
 	/**
 	 * @mode_valid:
 	 *

-- 
2.49.0