diff options
Diffstat (limited to 'recipes/linux/linux-omap-2.6.37/media/0012-media-Entity-use-count.patch')
| -rw-r--r-- | recipes/linux/linux-omap-2.6.37/media/0012-media-Entity-use-count.patch | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/recipes/linux/linux-omap-2.6.37/media/0012-media-Entity-use-count.patch b/recipes/linux/linux-omap-2.6.37/media/0012-media-Entity-use-count.patch new file mode 100644 index 0000000000..bc850e44a3 --- /dev/null +++ b/recipes/linux/linux-omap-2.6.37/media/0012-media-Entity-use-count.patch @@ -0,0 +1,176 @@ +From 3be6a2d10ff0cad0b240c65054da28395b014f82 Mon Sep 17 00:00:00 2001 +From: Laurent Pinchart <laurent.pinchart@ideasonboard.com> +Date: Sun, 7 Mar 2010 20:04:59 +0200 +Subject: [PATCH 12/43] media: Entity use count + +Due to the wide differences between drivers regarding power management +needs, the media controller does not implement power management. +However, the media_entity structure includes a use_count field that +media drivers can use to track the number of users of every entity for +power management needs. + +The use_count field is owned by media drivers and must not be touched by +entity drivers. Access to the field must be protected by the media +device graph_mutex lock. + +Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> +--- + Documentation/media-framework.txt | 13 ++++++++++ + drivers/media/media-device.c | 1 + + drivers/media/media-entity.c | 46 +++++++++++++++++++++++++++++++++++++ + include/media/media-device.h | 4 +++ + include/media/media-entity.h | 5 ++++ + 5 files changed, 69 insertions(+), 0 deletions(-) + +diff --git a/Documentation/media-framework.txt b/Documentation/media-framework.txt +index 88fe379..9017a41 100644 +--- a/Documentation/media-framework.txt ++++ b/Documentation/media-framework.txt +@@ -258,3 +258,16 @@ When the graph traversal is complete the function will return NULL. + + Graph traversal can be interrupted at any moment. No cleanup function call is + required and the graph structure can be freed normally. ++ ++ ++Use count and power handling ++---------------------------- ++ ++Due to the wide differences between drivers regarding power management needs, ++the media controller does not implement power management. However, the ++media_entity structure includes a use_count field that media drivers can use to ++track the number of users of every entity for power management needs. ++ ++The use_count field is owned by media drivers and must not be touched by entity ++drivers. Access to the field must be protected by the media device graph_mutex ++lock. +diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c +index b8a3ace..e4c2157 100644 +--- a/drivers/media/media-device.c ++++ b/drivers/media/media-device.c +@@ -73,6 +73,7 @@ int __must_check media_device_register(struct media_device *mdev) + mdev->entity_id = 1; + INIT_LIST_HEAD(&mdev->entities); + spin_lock_init(&mdev->lock); ++ mutex_init(&mdev->graph_mutex); + + /* Register the device node. */ + mdev->devnode.fops = &media_device_fops; +diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c +index a805f20..fe6bfd2 100644 +--- a/drivers/media/media-entity.c ++++ b/drivers/media/media-entity.c +@@ -23,6 +23,7 @@ + #include <linux/module.h> + #include <linux/slab.h> + #include <media/media-entity.h> ++#include <media/media-device.h> + + /** + * media_entity_init - Initialize a media entity +@@ -196,6 +197,51 @@ media_entity_graph_walk_next(struct media_entity_graph *graph) + EXPORT_SYMBOL_GPL(media_entity_graph_walk_next); + + /* ----------------------------------------------------------------------------- ++ * Module use count ++ */ ++ ++/* ++ * media_entity_get - Get a reference to the parent module ++ * @entity: The entity ++ * ++ * Get a reference to the parent media device module. ++ * ++ * The function will return immediately if @entity is NULL. ++ * ++ * Return a pointer to the entity on success or NULL on failure. ++ */ ++struct media_entity *media_entity_get(struct media_entity *entity) ++{ ++ if (entity == NULL) ++ return NULL; ++ ++ if (entity->parent->dev && ++ !try_module_get(entity->parent->dev->driver->owner)) ++ return NULL; ++ ++ return entity; ++} ++EXPORT_SYMBOL_GPL(media_entity_get); ++ ++/* ++ * media_entity_put - Release the reference to the parent module ++ * @entity: The entity ++ * ++ * Release the reference count acquired by media_entity_get(). ++ * ++ * The function will return immediately if @entity is NULL. ++ */ ++void media_entity_put(struct media_entity *entity) ++{ ++ if (entity == NULL) ++ return; ++ ++ if (entity->parent->dev) ++ module_put(entity->parent->dev->driver->owner); ++} ++EXPORT_SYMBOL_GPL(media_entity_put); ++ ++/* ----------------------------------------------------------------------------- + * Links management + */ + +diff --git a/include/media/media-device.h b/include/media/media-device.h +index 0b1ecf5..260d59c 100644 +--- a/include/media/media-device.h ++++ b/include/media/media-device.h +@@ -25,6 +25,7 @@ + + #include <linux/device.h> + #include <linux/list.h> ++#include <linux/mutex.h> + #include <linux/spinlock.h> + + #include <media/media-devnode.h> +@@ -42,6 +43,7 @@ + * @entity_id: ID of the next entity to be registered + * @entities: List of registered entities + * @lock: Entities list lock ++ * @graph_mutex: Entities graph operation lock + * + * This structure represents an abstract high-level media device. It allows easy + * access to entities and provides basic media device-level support. The +@@ -69,6 +71,8 @@ struct media_device { + + /* Protects the entities list */ + spinlock_t lock; ++ /* Serializes graph operations. */ ++ struct mutex graph_mutex; + }; + + /* media_devnode to media_device */ +diff --git a/include/media/media-entity.h b/include/media/media-entity.h +index b82f824..114541a 100644 +--- a/include/media/media-entity.h ++++ b/include/media/media-entity.h +@@ -81,6 +81,8 @@ struct media_entity { + struct media_pad *pads; /* Pads array (num_pads elements) */ + struct media_link *links; /* Links array (max_links elements)*/ + ++ int use_count; /* Use count for the entity. */ ++ + union { + /* Node specifications */ + struct { +@@ -129,6 +131,9 @@ void media_entity_cleanup(struct media_entity *entity); + int media_entity_create_link(struct media_entity *source, u16 source_pad, + struct media_entity *sink, u16 sink_pad, u32 flags); + ++struct media_entity *media_entity_get(struct media_entity *entity); ++void media_entity_put(struct media_entity *entity); ++ + void media_entity_graph_walk_start(struct media_entity_graph *graph, + struct media_entity *entity); + struct media_entity * +-- +1.6.6.1 + |