From 293a8fd7721a90987d9bf149feab60e756dac269 Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Tue, 16 Dec 2025 18:58:34 +0100 Subject: [PATCH] drm/bridge: add of_drm_find_and_get_bridge() of_drm_find_bridge() does not increment the refcount for the returned bridge, but that is required now. However converting it and all its users is not realistically doable at once given the large amount of (direct and indirect) callers and the complexity of some. Solve this issue by creating a new of_drm_find_and_get_bridge() function that is identical to of_drm_find_bridge() except also it takes a reference. Then of_drm_find_bridge() will be deprecated to be eventually removed. Suggested-by: Maxime Ripard Link: https://lore.kernel.org/dri-devel/20250319-stylish-lime-mongoose-0a18ad@houat/ Reviewed-by: Maxime Ripard Link: https://patch.msgid.link/20251216-drm-bridge-alloc-getput-drm_of_find_bridge-v3-1-b5165fab8058@bootlin.com Signed-off-by: Luca Ceresoli --- drivers/gpu/drm/drm_bridge.c | 25 +++++++++++++++++++++++++ include/drm/drm_bridge.h | 5 +++++ 2 files changed, 30 insertions(+) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index db40c26d1cb3..0dbc8b59c3be 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -1479,6 +1479,31 @@ void drm_bridge_hpd_notify(struct drm_bridge *bridge, EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify); #ifdef CONFIG_OF +/** + * of_drm_find_and_get_bridge - find the bridge corresponding to the device + * node in the global bridge list + * @np: device node + * + * The refcount of the returned bridge is incremented. Use drm_bridge_put() + * when done with it. + * + * RETURNS: + * drm_bridge control struct on success, NULL on failure + */ +struct drm_bridge *of_drm_find_and_get_bridge(struct device_node *np) +{ + struct drm_bridge *bridge; + + scoped_guard(mutex, &bridge_lock) { + list_for_each_entry(bridge, &bridge_list, list) + if (bridge->of_node == np) + return drm_bridge_get(bridge); + } + + return NULL; +} +EXPORT_SYMBOL(of_drm_find_and_get_bridge); + /** * of_drm_find_bridge - find the bridge corresponding to the device node in * the global bridge list diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 68b9da1eb542..42ec33116d18 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -1326,8 +1326,13 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, enum drm_bridge_attach_flags flags); #ifdef CONFIG_OF +struct drm_bridge *of_drm_find_and_get_bridge(struct device_node *np); struct drm_bridge *of_drm_find_bridge(struct device_node *np); #else +static inline struct drm_bridge *of_drm_find_and_get_bridge(struct device_node *np) +{ + return NULL; +} static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np) { return NULL; -- 2.47.3