lkml.org 
[lkml]   [2019]   [Jul]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.19 87/91] staging: bcm2835-camera: Replace spinlock protecting context_map with mutex
Date
From: Dave Stevenson <dave.stevenson@raspberrypi.org>

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: 950fd867c635 ("staging: bcm2835-camera: Replace open-coded idr with a struct idr.")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

--- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
@@ -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_instan
* 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_cont
{
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_in

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;

\
 
 \ /
  Last update: 2019-07-12 14:41    [W:0.262 / U:13.888 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site