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Commit 4502c43d authored by Dave Stevenson's avatar Dave Stevenson Committed by Greg Kroah-Hartman
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staging: bcm2835-camera: Replace spinlock protecting context_map with mutex 



commit 8dedab2903f152aa3cee9ae3d57c828dea0d356e upstream.

The commit "staging: bcm2835-camera: Replace open-coded idr with a struct idr."
replaced an internal implementation of an idr with the standard functions
and a spinlock. idr_alloc(GFP_KERNEL) can sleep whilst calling kmem_cache_alloc
to allocate the new node, but this is not valid whilst in an atomic context
due to the spinlock.

There is no need for this to be a spinlock as a standard mutex is
sufficient.

Fixes: 950fd867 ("staging: bcm2835-camera: Replace open-coded idr with a struct idr.")
Signed-off-by: default avatarDave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: default avatarStefan Wahren <wahrenst@gmx.net>
Acked-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 22a20b9f

drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c

+7 −6
Original line number Diff line number Diff line
@@ -162,7 +162,8 @@ struct vchiq_mmal_instance { 
	void *bulk_scratch;



	struct idr context_map;

	spinlock_t context_map_lock;

	/* protect accesses to context_map */

	struct mutex context_map_lock;



	/* component to use next */

	int component_idx;
@@ -185,10 +186,10 @@ get_msg_context(struct vchiq_mmal_instance *instance) 
	 * that when we service the VCHI reply, we can look up what

	 * message is being replied to.

	 */

	spin_lock(&instance->context_map_lock);

	mutex_lock(&instance->context_map_lock);

	handle = idr_alloc(&instance->context_map, msg_context,

			   0, 0, GFP_KERNEL);

	spin_unlock(&instance->context_map_lock);

	mutex_unlock(&instance->context_map_lock);



	if (handle < 0) {

		kfree(msg_context);
@@ -212,9 +213,9 @@ release_msg_context(struct mmal_msg_context *msg_context) 
{

	struct vchiq_mmal_instance *instance = msg_context->instance;



	spin_lock(&instance->context_map_lock);

	mutex_lock(&instance->context_map_lock);

	idr_remove(&instance->context_map, msg_context->handle);

	spin_unlock(&instance->context_map_lock);

	mutex_unlock(&instance->context_map_lock);

	kfree(msg_context);

}
@@ -1854,7 +1855,7 @@ int vchiq_mmal_init(struct vchiq_mmal_instance **out_instance) 


	instance->bulk_scratch = vmalloc(PAGE_SIZE);



	spin_lock_init(&instance->context_map_lock);

	mutex_init(&instance->context_map_lock);

	idr_init_base(&instance->context_map, 1);



	params.callback_param = instance;