linux-kernel - [PATCH 1/2] drm/connector: allow a .destroy callback for drmm-allocated connectors

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Message-Id: <20250925-drm-bridge-alloc-getput-bridge-connector-v1-1-f0736e1c73ee@bootlin.com>
Date: Thu, 25 Sep 2025 19:19:49 +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>, 
 Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Cc: 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 1/2] drm/connector: allow a .destroy callback for
 drmm-allocated connectors

Some code is going to need connector-specific cleanup actions (namely
drm_bridge_connector will need to put refcounted bridges).

The .destroy callback is appropriate for this task but it is currently
forbidden by drmm_connector_init(). Relax this limitation and document it.

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

---

The other obvious approach would be adding a separate .cleanup callback for
the cleanup-only actions. I tried both, they both apparently work, so any
arguments and opinions on which approach is best within the overall DRM
design would be very useful here.
---
 drivers/gpu/drm/drm_connector.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 272d6254ea4784e97ca894ec4d463beebf9fdbf0..bd0220513a23afcb096b0c4c4d2b957b81f21ee1 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -513,7 +513,8 @@ static void drm_connector_cleanup_action(struct drm_device *dev,
  *
  * The connector structure should be allocated with drmm_kzalloc().
  *
- * The @drm_connector_funcs.destroy hook must be NULL.
+ * The @drm_connector_funcs.destroy hook must only do connector-specific
+ * cleanups if any is needed, not dealloacte the connector.
  *
  * Returns:
  * Zero on success, error code on failure.
@@ -526,9 +527,6 @@ int drmm_connector_init(struct drm_device *dev,
 {
 	int ret;
 
-	if (drm_WARN_ON(dev, funcs && funcs->destroy))
-		return -EINVAL;
-
 	ret = drm_connector_init_and_add(dev, connector, funcs, connector_type, ddc);
 	if (ret)
 		return ret;

-- 
2.51.0