From: Luca Ceresoli <luca.ceresoli@bootlin•com>
To: Maarten Lankhorst <maarten.lankhorst@linux•intel.com>,
Maxime Ripard <mripard@kernel•org>,
Thomas Zimmermann <tzimmermann@suse•de>,
David Airlie <airlied@gmail•com>,
Simona Vetter <simona@ffwll•ch>,
Andrzej Hajda <andrzej.hajda@intel•com>,
Neil Armstrong <neil.armstrong@linaro•org>,
Robert Foss <rfoss@kernel•org>,
Laurent Pinchart <Laurent.pinchart@ideasonboard•com>,
Jonas Karlman <jonas@kwiboo•se>,
Jernej Skrabec <jernej.skrabec@gmail•com>,
Inki Dae <inki.dae@samsung•com>,
Jagan Teki <jagan@amarulasolutions•com>,
Marek Szyprowski <m.szyprowski@samsung•com>,
Marek Vasut <marex@denx•de>, Stefan Agner <stefan@agner•ch>,
Frank Li <Frank.Li@nxp•com>,
Sascha Hauer <s.hauer@pengutronix•de>,
Pengutronix Kernel Team <kernel@pengutronix•de>,
Fabio Estevam <festevam@gmail•com>
Cc: Hui Pu <Hui.Pu@gehealthcare•com>,
Ian Ray <ian.ray@gehealthcare•com>,
Thomas Petazzoni <thomas.petazzoni@bootlin•com>,
dri-devel@lists•freedesktop.org, linux-kernel@vger•kernel.org,
imx@lists•linux.dev, linux-arm-kernel@lists•infradead.org,
Luca Ceresoli <luca.ceresoli@bootlin•com>
Subject: [PATCH 15/37] drm/display: bridge-connector: allocate the connector dynamically
Date: Tue, 19 May 2026 12:37:32 +0200 [thread overview]
Message-ID: <20260519-drm-bridge-hotplug-v1-15-45e2bdb3dfb4@bootlin.com> (raw)
In-Reply-To: <20260519-drm-bridge-hotplug-v1-0-45e2bdb3dfb4@bootlin.com>
Currently the drm_bridge_connector has an embedded drm_connector, so their
allocation lifetimes are tied to each other. This is insufficient to
support DRM bridge hotplugging, which requires the connector to be added
and removed dynamically at runtime multiple times based on hotplug/unplug
events while the drm_bridge_connector is persistent.
Moreover the drm_connector is exposed to user space and thus an ongoing
operation (e.g. an ioctl) might last for an arbitrarily long time even
after the hardware gets removed. This means a new connector might have to
be added when the previous one is still referenced by user space.
In preparation to handle hotplug, allocate the drm-connector dynamically,
to allow:
* creating and destroying a connector multiple times during a single
drm_bridge_connector lifetime
* creating a new connector even though the previous one is still in use
and thus still refcounted and not yet freed
This commit does not introduce the actions in the two bullets (it will
happen in a later commit), it only moves to dynamic APIs for connector
allocation and init.
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin•com>
---
drivers/gpu/drm/display/drm_bridge_connector.c | 156 ++++++++++++++++++-------
1 file changed, 114 insertions(+), 42 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 1fd104f1647b..b4e2c8f1d32d 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -1,6 +1,8 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard•com>
+ * Copyright (C) 2026 GE HealthCare
+ * Author: Luca Ceresoli <luca.ceresoli@bootlin•com>
*/
#include <linux/export.h>
@@ -53,13 +55,24 @@
*/
/**
- * struct drm_bridge_connector - A connector backed by a chain of bridges
+ * drm_bridge_connector_dynconn - wrapper struct for the dynamically
+ * created drm_connector
*/
-struct drm_bridge_connector {
+struct drm_bridge_connector_dynconn {
/**
- * @base: The base DRM connector
+ * @bridge_connector: the owning bridge connector
*/
- struct drm_connector base;
+ struct drm_bridge_connector *bridge_connector;
+ /**
+ * @connector: the drm_connector exposed to user space
+ */
+ struct drm_connector connector;
+};
+
+/**
+ * struct drm_bridge_connector - A connector backed by a chain of bridges
+ */
+struct drm_bridge_connector {
/**
* @drm: The DRM device we belong to
*/
@@ -70,6 +83,10 @@ struct drm_bridge_connector {
* The encoder at the start of the bridges chain.
*/
struct drm_encoder *encoder;
+ /**
+ * @dynconn: The DRM connector added by the drm_bridge_connector
+ */
+ struct drm_bridge_connector_dynconn *dynconn;
/**
* @bridge_edid:
*
@@ -137,8 +154,13 @@ struct drm_bridge_connector {
struct drm_connector_hdmi_funcs hdmi_funcs;
};
-#define to_drm_bridge_connector(x) \
- container_of(x, struct drm_bridge_connector, base)
+static struct drm_bridge_connector *to_drm_bridge_connector(const struct drm_connector *connector)
+{
+ const struct drm_bridge_connector_dynconn *dynconn =
+ container_of(connector, struct drm_bridge_connector_dynconn, connector);
+
+ return dynconn->bridge_connector;
+}
static void drm_bridge_connector_put_bridges(struct drm_bridge_connector *bridge_connector)
{
@@ -152,13 +174,6 @@ static void drm_bridge_connector_put_bridges(struct drm_bridge_connector *bridge
drm_bridge_put(bridge_connector->bridge_hdmi_cec);
}
-static void drmm_bridge_connector_put_bridges(struct drm_device *dev, void *data)
-{
- struct drm_bridge_connector *bridge_connector = (struct drm_bridge_connector *)data;
-
- drm_bridge_connector_put_bridges(bridge_connector);
-}
-
/* -----------------------------------------------------------------------------
* Bridge Connector Hot-Plug Handling
*/
@@ -179,7 +194,7 @@ static void drm_bridge_connector_hpd_notify(struct drm_connector *connector,
static void drm_bridge_connector_handle_hpd(struct drm_bridge_connector *bridge_connector,
enum drm_connector_status status)
{
- struct drm_connector *connector = &bridge_connector->base;
+ struct drm_connector *connector = &bridge_connector->dynconn->connector;
struct drm_device *dev = bridge_connector->drm;
mutex_lock(&dev->mode_config.mutex);
@@ -299,6 +314,16 @@ static void drm_bridge_connector_reset(struct drm_connector *connector)
connector->state);
}
+static void drm_bridge_connector_dynconn_destroy(struct drm_connector *connector)
+{
+ struct drm_bridge_connector_dynconn *dynconn =
+ container_of(connector, struct drm_bridge_connector_dynconn, connector);
+
+ drm_connector_cleanup(connector);
+ drm_bridge_connector_put_bridges(dynconn->bridge_connector);
+ kfree(dynconn);
+}
+
static const struct drm_connector_funcs drm_bridge_connector_funcs = {
.reset = drm_bridge_connector_reset,
.detect = drm_bridge_connector_detect,
@@ -308,6 +333,7 @@ static const struct drm_connector_funcs drm_bridge_connector_funcs = {
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
.debugfs_init = drm_bridge_connector_debugfs_init,
.oob_hotplug_event = drm_bridge_connector_oob_hotplug_event,
+ .destroy = drm_bridge_connector_dynconn_destroy,
};
/* -----------------------------------------------------------------------------
@@ -777,7 +803,17 @@ static const struct drm_connector_hdmi_cec_funcs drm_bridge_connector_hdmi_cec_f
* Bridge Connector Initialisation
*/
-static int drm_bridge_connector_get_bridges(struct drm_bridge_connector *bridge_connector,
+static void drm_bridge_connector_dynconn_release(struct drm_bridge_connector *bridge_connector)
+{
+ if (!bridge_connector->dynconn)
+ return;
+
+ drm_connector_unregister(&bridge_connector->dynconn->connector);
+ drm_connector_put(&bridge_connector->dynconn->connector);
+ bridge_connector->dynconn = NULL;
+}
+
+static int drm_bridge_connector_get_bridges(struct drm_bridge_connector_dynconn *dynconn,
int *connector_type,
unsigned int *supported_formats,
unsigned int *max_bpc,
@@ -785,7 +821,8 @@ static int drm_bridge_connector_get_bridges(struct drm_bridge_connector *bridge_
struct drm_bridge **panel_bridge,
bool *support_hdcp)
{
- struct drm_connector *connector = &bridge_connector->base;
+ struct drm_bridge_connector *bridge_connector = dynconn->bridge_connector;
+ struct drm_connector *connector = &dynconn->connector;
/*
* TODO: Handle doublescan_allowed and stereo_allowed.
@@ -937,6 +974,7 @@ static int drm_bridge_connector_get_bridges(struct drm_bridge_connector *bridge_
static int drm_bridge_connector_init_hdmi_audio_cec(struct drm_bridge_connector *bridge_connector)
{
+ struct drm_connector *connector = &bridge_connector->dynconn->connector;
int ret;
if (bridge_connector->bridge_hdmi_audio ||
@@ -951,7 +989,7 @@ static int drm_bridge_connector_init_hdmi_audio_cec(struct drm_bridge_connector
dev = bridge->hdmi_audio_dev;
- ret = drm_connector_hdmi_audio_init(&bridge_connector->base, dev,
+ ret = drm_connector_hdmi_audio_init(connector, dev,
&drm_bridge_connector_hdmi_audio_funcs,
bridge->hdmi_audio_max_i2s_playback_channels,
bridge->hdmi_audio_i2s_formats,
@@ -965,8 +1003,7 @@ static int drm_bridge_connector_init_hdmi_audio_cec(struct drm_bridge_connector
bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER) {
struct drm_bridge *bridge = bridge_connector->bridge_hdmi_cec;
- ret = drmm_connector_hdmi_cec_notifier_register(&bridge_connector->base,
- NULL,
+ ret = drmm_connector_hdmi_cec_notifier_register(connector, NULL,
bridge->hdmi_cec_dev);
if (ret)
return ret;
@@ -976,7 +1013,7 @@ static int drm_bridge_connector_init_hdmi_audio_cec(struct drm_bridge_connector
bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) {
struct drm_bridge *bridge = bridge_connector->bridge_hdmi_cec;
- ret = drmm_connector_hdmi_cec_register(&bridge_connector->base,
+ ret = drmm_connector_hdmi_cec_register(connector,
&drm_bridge_connector_hdmi_cec_funcs,
bridge->hdmi_cec_adapter_name,
bridge->hdmi_cec_available_las,
@@ -1009,13 +1046,20 @@ static int drm_bridge_connector_add_connector(struct drm_bridge_connector *bridg
int connector_type;
int ret;
- connector = &bridge_connector->base;
+ struct drm_bridge_connector_dynconn *dynconn = kzalloc_obj(*dynconn);
+ if (!dynconn)
+ return -ENOMEM;
- ret = drm_bridge_connector_get_bridges(bridge_connector, &connector_type,
+ dynconn->bridge_connector = bridge_connector;
+ connector = &dynconn->connector;
+
+ ret = drm_bridge_connector_get_bridges(dynconn, &connector_type,
&supported_formats, &max_bpc, &ddc,
&panel_bridge, &support_hdcp);
- if (ret)
+ if (ret) {
+ kfree(dynconn);
return ret;
+ }
if (bridge_connector->bridge_hdmi) {
if (!connector->ycbcr_420_allowed)
@@ -1035,25 +1079,34 @@ static int drm_bridge_connector_add_connector(struct drm_bridge_connector *bridg
bridge_connector->hdmi_funcs.spd =
drm_bridge_connector_hdmi_spd_infoframe;
- ret = drmm_connector_hdmi_init(bridge_connector->drm, connector,
- bridge_connector->bridge_hdmi->vendor,
- bridge_connector->bridge_hdmi->product,
- &drm_bridge_connector_funcs,
- &bridge_connector->hdmi_funcs,
- connector_type, ddc,
- supported_formats,
- max_bpc);
+ ret = drm_connector_hdmi_dynamic_init(bridge_connector->drm, connector,
+ bridge_connector->bridge_hdmi->vendor,
+ bridge_connector->bridge_hdmi->product,
+ &drm_bridge_connector_funcs,
+ &bridge_connector->hdmi_funcs,
+ connector_type, ddc,
+ supported_formats,
+ max_bpc);
} else {
- ret = drmm_connector_init(bridge_connector->drm, connector,
- &drm_bridge_connector_funcs,
- connector_type, ddc);
+ ret = drm_connector_dynamic_init(bridge_connector->drm, connector,
+ &drm_bridge_connector_funcs,
+ connector_type, ddc);
}
- if (ret)
+ if (ret) {
+ drm_bridge_connector_put_bridges(dynconn->bridge_connector);
+ kfree(dynconn);
return ret;
+ }
+
+ /* From now on the connector is referenced and has to be put, not kfreed */
+
+ bridge_connector->dynconn = dynconn;
+
+ drm_bridge_connector_reset(connector);
ret = drm_bridge_connector_init_hdmi_audio_cec(bridge_connector);
if (ret)
- return ret;
+ goto err_put;
drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
@@ -1072,9 +1125,25 @@ static int drm_bridge_connector_add_connector(struct drm_bridge_connector *bridg
ret = drm_connector_attach_encoder(connector, bridge_connector->encoder);
if (ret)
- return ret;
+ goto err_put;
+
+ ret = drm_connector_dynamic_register(connector);
+ if (ret)
+ goto err_put;
return 0;
+
+err_put:
+ drm_connector_put(connector);
+ bridge_connector->dynconn = NULL;
+ return ret;
+}
+
+static void drm_bridge_connector_fini(struct drm_device *dev, void *res)
+{
+ struct drm_bridge_connector *bridge_connector = (struct drm_bridge_connector *)res;
+
+ drm_bridge_connector_dynconn_release(bridge_connector);
}
/**
@@ -1104,10 +1173,6 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
if (!bridge_connector)
return ERR_PTR(-ENOMEM);
- ret = drmm_add_action(drm, drmm_bridge_connector_put_bridges, bridge_connector);
- if (ret)
- return ERR_PTR(ret);
-
bridge_connector->drm = drm;
bridge_connector->encoder = encoder;
@@ -1115,6 +1180,13 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
if (ret)
return ERR_PTR(ret);
- return &bridge_connector->base;
+ ret = drmm_add_action_or_reset(drm, drm_bridge_connector_fini, bridge_connector);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (!bridge_connector->dynconn)
+ return ERR_PTR(-EINVAL);
+
+ return &bridge_connector->dynconn->connector;
}
EXPORT_SYMBOL_GPL(drm_bridge_connector_init);
--
2.54.0
next prev parent reply other threads:[~2026-05-19 10:39 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-19 10:37 [PATCH 00/37] drm bridge hotplug Luca Ceresoli
2026-05-19 10:37 ` [PATCH 01/37] drm/connector: split drmm_connector_hdmi_init() in 3 parts Luca Ceresoli
2026-05-19 10:37 ` [PATCH 02/37] drm/connector: add drm_connector_hdmi_dynamic_init() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 03/37] drm/display: bridge-connector: rename variable for consistency Luca Ceresoli
2026-05-19 10:37 ` [PATCH 04/37] drm/display: bridge-connector: store the drm_device pointer Luca Ceresoli
2026-05-19 10:37 ` [PATCH 05/37] drm/display: bridge-connector: split code creating the connector to a subfunction Luca Ceresoli
2026-05-19 10:37 ` [PATCH 06/37] drm/display: bridge-connector: use a drm_bridge_connector internally, not a drm_connector Luca Ceresoli
2026-05-19 10:37 ` [PATCH 07/37] drm/display: bridge-connector: extract drm_bridge_connector_get_bridges() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 08/37] drm/display: bridge-connector: return int from drm_bridge_connector_get_bridges() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 09/37] drm/display: bridge-connector: extract drm_bridge_connector_init_hdmi_audio_cec() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 10/37] drm/display: bridge-connector: return int from drm_bridge_connector_init_hdmi_audio_cec() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 11/37] drm/display: bridge-connector: return int from drm_bridge_connector_add_connector() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 12/37] drm/display: bridge-connector: hoist error management to common code Luca Ceresoli
2026-05-19 10:37 ` [PATCH 13/37] drm/display: bridge-connector: move drm_bridge_connector_put_bridges() definition eariler Luca Ceresoli
2026-05-19 10:37 ` [PATCH 14/37] drm/display: bridge-connector: add non-drmm variant of drm_bridge_connector_put_bridges() Luca Ceresoli
2026-05-19 10:37 ` Luca Ceresoli [this message]
2026-05-19 10:37 ` [PATCH 16/37] drm/display: bridge-connector: move per-connector fields to the dynamic connector Luca Ceresoli
2026-05-19 10:37 ` [PATCH 17/37] drm/display: bridge-connector: protect dynconn creation and destruction with a mutex Luca Ceresoli
2026-05-19 10:37 ` [PATCH 18/37] drm/bridge: samsung-dsim: remove the panel_bridge on host_detach Luca Ceresoli
2026-05-19 10:37 ` [PATCH 19/37] drm/bridge: samsung-dsim: move drm_bridge_add() call to probe Luca Ceresoli
2026-05-19 10:37 ` [PATCH 20/37] drm/bridge: samsung-dsim: attach: return -EPROBE_DEFER is next bridge not yet available Luca Ceresoli
2026-05-19 10:37 ` [PATCH 21/37] drm/bridge: initialize chain_node list head on allocation Luca Ceresoli
2026-05-19 10:37 ` [PATCH 22/37] drm/bridge: initialize chain_node list head on detach and attach errors Luca Ceresoli
2026-05-19 10:37 ` [PATCH 23/37] drm/encoder: add drm_encoder_cleanup_from() Luca Ceresoli
2026-05-19 10:37 ` [PATCH 24/37] drm/atomic: move drm_atomic_helper_disable_all() and drm_atomic_helper_shutdown() from drm_atomic_helper to drm_atomic Luca Ceresoli
2026-05-19 10:37 ` [PATCH 25/37] drm/bridge: shutdown and cleanup on bridge unplug Luca Ceresoli
2026-05-19 10:37 ` [PATCH 26/37] drm: event-notifier: add mechanism to notify about hotplug events Luca Ceresoli
2026-05-19 10:37 ` [PATCH 27/37] drm/bridge: notify about detached bridges Luca Ceresoli
2026-05-19 10:37 ` [PATCH 28/37] drm/mipi-dsi: turn DRM_MIPI_DSI into a tristate Luca Ceresoli
2026-05-19 10:37 ` [PATCH 29/37] drm/mipi-dsi: notify about DSI attach Luca Ceresoli
2026-05-19 10:37 ` [PATCH 30/37] drm/bridge: add drm_bridge_is_tail() to know whether a bridge completes the pipeline Luca Ceresoli
2026-05-19 10:37 ` [PATCH 31/37] drm/bridge: panel: implement .is_tail Luca Ceresoli
2026-05-19 15:12 ` Neil Armstrong
2026-05-19 10:37 ` [PATCH 32/37] drm/bridge: display-connector: " Luca Ceresoli
2026-05-19 10:37 ` [PATCH 33/37] drm/bridge: samsung-dsim: " Luca Ceresoli
2026-05-19 10:37 ` [PATCH 34/37] drm/bridge: ti-sn65dsi83: " Luca Ceresoli
2026-05-19 10:37 ` [PATCH 35/37] drm/bridge: drm_bridge_attach(): don't fail on -EPROBE_DEFER Luca Ceresoli
2026-05-19 10:37 ` [PATCH 36/37] drm/display: bridge-connector: handle bridge hotplug Luca Ceresoli
2026-05-19 10:37 ` [PATCH 37/37] drm/mxsfb/lcdif: enable " Luca Ceresoli
2026-06-01 15:44 ` [PATCH 00/37] drm " Luca Ceresoli
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