[RFC][PATCH 3/3] staging: ion: Avoid using rt_mutexes directly.

From: John Stultz
Date: Mon Dec 16 2013 - 16:33:17 EST


RT_MUTEXES can be configured out of the kernel, causing compile
problems with ION.

Since there is no documentation as to why directly using rt_mutexes
is necessary (and very few drivers directly use rt_mutexes), simply
convert the ion_heap lock to a normal mutex.

Cc: Colin Cross <ccross@xxxxxxxxxxx>
Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Reported-by: Jim Davis <jim.epost@xxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/staging/android/ion/ion_heap.c | 20 ++++++++++----------
drivers/staging/android/ion/ion_priv.h | 2 +-
2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
index 9cf5622..88685da 100644
--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -160,10 +160,10 @@ int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot)

void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer)
{
- rt_mutex_lock(&heap->lock);
+ mutex_lock(&heap->lock);
list_add(&buffer->list, &heap->free_list);
heap->free_list_size += buffer->size;
- rt_mutex_unlock(&heap->lock);
+ mutex_unlock(&heap->lock);
wake_up(&heap->waitqueue);
}

@@ -171,9 +171,9 @@ size_t ion_heap_freelist_size(struct ion_heap *heap)
{
size_t size;

- rt_mutex_lock(&heap->lock);
+ mutex_lock(&heap->lock);
size = heap->free_list_size;
- rt_mutex_unlock(&heap->lock);
+ mutex_unlock(&heap->lock);

return size;
}
@@ -186,7 +186,7 @@ size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size)
if (ion_heap_freelist_size(heap) == 0)
return 0;

- rt_mutex_lock(&heap->lock);
+ mutex_lock(&heap->lock);
if (size == 0)
size = heap->free_list_size;

@@ -198,7 +198,7 @@ size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size)
total_drained += buffer->size;
ion_buffer_destroy(buffer);
}
- rt_mutex_unlock(&heap->lock);
+ mutex_unlock(&heap->lock);

return total_drained;
}
@@ -213,16 +213,16 @@ static int ion_heap_deferred_free(void *data)
wait_event_freezable(heap->waitqueue,
ion_heap_freelist_size(heap) > 0);

- rt_mutex_lock(&heap->lock);
+ mutex_lock(&heap->lock);
if (list_empty(&heap->free_list)) {
- rt_mutex_unlock(&heap->lock);
+ mutex_unlock(&heap->lock);
continue;
}
buffer = list_first_entry(&heap->free_list, struct ion_buffer,
list);
list_del(&buffer->list);
heap->free_list_size -= buffer->size;
- rt_mutex_unlock(&heap->lock);
+ mutex_unlock(&heap->lock);
ion_buffer_destroy(buffer);
}

@@ -235,7 +235,7 @@ int ion_heap_init_deferred_free(struct ion_heap *heap)

INIT_LIST_HEAD(&heap->free_list);
heap->free_list_size = 0;
- rt_mutex_init(&heap->lock);
+ mutex_init(&heap->lock);
init_waitqueue_head(&heap->waitqueue);
heap->task = kthread_run(ion_heap_deferred_free, heap,
"%s", heap->name);
diff --git a/drivers/staging/android/ion/ion_priv.h b/drivers/staging/android/ion/ion_priv.h
index fc8a4c3..df81ce1 100644
--- a/drivers/staging/android/ion/ion_priv.h
+++ b/drivers/staging/android/ion/ion_priv.h
@@ -159,7 +159,7 @@ struct ion_heap {
struct shrinker shrinker;
struct list_head free_list;
size_t free_list_size;
- struct rt_mutex lock;
+ struct mutex lock;
wait_queue_head_t waitqueue;
struct task_struct *task;
int (*debug_show)(struct ion_heap *heap, struct seq_file *, void *);
--
1.8.3.2

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