[PATCH 03/31] staging: bcm2835-camera: Replace spinlock protecting context_map with mutex
From: Stefan Wahren <wahrenst@gmx.net>
Date: 2019-06-27 18:57:14
Also in:
linux-media
Subsystem:
staging subsystem, the rest · Maintainers:
Greg Kroah-Hartman, Linus Torvalds
From: Dave Stevenson <redacted>
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 <redacted>
---
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; --
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