From a08fad1ec80c69c79b3ffb6d84968b0952d32da1 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 9 Dec 2015 19:47:35 -0200 Subject: [PATCH] [media] media-entity: protect object creation/removal using spin lock Some parts of the media controller are using mutexes while others are using spin locks in order to protect creation and removal of elements in the graph. That's wrong! Also, the V4L2 core can remove graph elements on non-interactive context: BUG: sleeping function called from invalid context at include/linux/sched.h:2776 Fix it by always using spin locks for graph element addition/removal, just like entity creation/removal is protected at media-device.c Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-entity.c | 16 ++++++++-------- include/media/media-device.h | 2 +- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index ee0f81364960..b1390d843909 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -700,9 +700,9 @@ void media_entity_remove_links(struct media_entity *entity) if (entity->graph_obj.mdev == NULL) return; - mutex_lock(&entity->graph_obj.mdev->graph_mutex); + spin_lock(&entity->graph_obj.mdev->lock); __media_entity_remove_links(entity); - mutex_unlock(&entity->graph_obj.mdev->graph_mutex); + spin_unlock(&entity->graph_obj.mdev->lock); } EXPORT_SYMBOL_GPL(media_entity_remove_links); @@ -792,9 +792,9 @@ int media_entity_setup_link(struct media_link *link, u32 flags) { int ret; - mutex_lock(&link->source->entity->graph_obj.mdev->graph_mutex); + spin_lock(&link->source->entity->graph_obj.mdev->lock); ret = __media_entity_setup_link(link, flags); - mutex_unlock(&link->source->entity->graph_obj.mdev->graph_mutex); + spin_unlock(&link->source->entity->graph_obj.mdev->lock); return ret; } @@ -932,9 +932,9 @@ EXPORT_SYMBOL_GPL(__media_remove_intf_link); void media_remove_intf_link(struct media_link *link) { - mutex_lock(&link->graph_obj.mdev->graph_mutex); + spin_lock(&link->graph_obj.mdev->lock); __media_remove_intf_link(link); - mutex_unlock(&link->graph_obj.mdev->graph_mutex); + spin_unlock(&link->graph_obj.mdev->lock); } EXPORT_SYMBOL_GPL(media_remove_intf_link); @@ -954,8 +954,8 @@ void media_remove_intf_links(struct media_interface *intf) if (intf->graph_obj.mdev == NULL) return; - mutex_lock(&intf->graph_obj.mdev->graph_mutex); + spin_lock(&intf->graph_obj.mdev->lock); __media_remove_intf_links(intf); - mutex_unlock(&intf->graph_obj.mdev->graph_mutex); + spin_unlock(&intf->graph_obj.mdev->lock); } EXPORT_SYMBOL_GPL(media_remove_intf_links); diff --git a/include/media/media-device.h b/include/media/media-device.h index 1b12774a9ab4..87ff299e1265 100644 --- a/include/media/media-device.h +++ b/include/media/media-device.h @@ -88,7 +88,7 @@ struct media_device { struct list_head pads; struct list_head links; - /* Protects the entities list */ + /* Protects the graph objects creation/removal */ spinlock_t lock; /* Serializes graph operations. */ struct mutex graph_mutex; -- 2.39.5