[PATCH V2 02/29] staging: bcm2835-camera: Replace spinlock protecting context_map with mutex
Stefan Wahren
wahrenst at gmx.net
Sat Jun 29 12:13:17 UTC 2019
From: Dave Stevenson <dave.stevenson at raspberrypi.org>
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: 950fd867c635 ("staging: bcm2835-camera: Replace open-coded idr with a struct idr.")
Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.org>
Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
Acked-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung at kernel.org>
---
drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
index 16af735..f1bb900 100644
--- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
@@ -161,7 +161,8 @@ 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;
@@ -184,10 +185,10 @@ 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);
@@ -211,9 +212,9 @@ 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);
}
@@ -1849,7 +1850,7 @@ 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;
--
2.7.4
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