Commit 293a8fd7 authored by Luca Ceresoli's avatar Luca Ceresoli
Browse files

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: default avatarMaxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/dri-devel/20250319-stylish-lime-mongoose-0a18ad@houat/


Reviewed-by: default avatarMaxime Ripard <mripard@kernel.org>
Link: https://patch.msgid.link/20251216-drm-bridge-alloc-getput-drm_of_find_bridge-v3-1-b5165fab8058@bootlin.com


Signed-off-by: default avatarLuca Ceresoli <luca.ceresoli@bootlin.com>
parent 130343ee

drivers/gpu/drm/drm_bridge.c

+25 −0
Original line number Diff line number Diff line
@@ -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

include/drm/drm_bridge.h

+5 −0
Original line number Diff line number Diff line
@@ -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;