It is preferred in the kernel to avoid using semaphores to wait for events, as they are optimised for the opposite situation; where the common case is that they are available and may block only occasionally. FYI see this thread: https://lkml.org/lkml/2008/4/11/323. Also completions are semantically more explicit in this case. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx> --- .../interface/vchiq_arm/vchiq_util.c | 16 ++++++++-------- .../interface/vchiq_arm/vchiq_util.h | 6 +++--- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c index 2e52f07bbaa9..44b954daa74a 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c @@ -48,8 +48,8 @@ int vchiu_queue_init(VCHIU_QUEUE_T *queue, int size) queue->write = 0; queue->initialized = 1; - sema_init(&queue->pop, 0); - sema_init(&queue->push, 0); + init_completion(&queue->pop); + init_completion(&queue->push); queue->storage = kcalloc(size, sizeof(VCHIQ_HEADER_T *), GFP_KERNEL); if (!queue->storage) { @@ -80,7 +80,7 @@ void vchiu_queue_push(VCHIU_QUEUE_T *queue, VCHIQ_HEADER_T *header) return; while (queue->write == queue->read + queue->size) { - if (down_interruptible(&queue->pop) != 0) + if (wait_for_completion_interruptible(&queue->pop)) flush_signals(current); } @@ -100,17 +100,17 @@ void vchiu_queue_push(VCHIU_QUEUE_T *queue, VCHIQ_HEADER_T *header) queue->write++; - up(&queue->push); + complete(&queue->push); } VCHIQ_HEADER_T *vchiu_queue_peek(VCHIU_QUEUE_T *queue) { while (queue->write == queue->read) { - if (down_interruptible(&queue->push) != 0) + if (wait_for_completion_interruptible(&queue->push)) flush_signals(current); } - up(&queue->push); // We haven't removed anything from the queue. + complete(&queue->push); // We haven't removed anything from the queue. /* * Read from queue->storage must be visible after read from @@ -126,7 +126,7 @@ VCHIQ_HEADER_T *vchiu_queue_pop(VCHIU_QUEUE_T *queue) VCHIQ_HEADER_T *header; while (queue->write == queue->read) { - if (down_interruptible(&queue->push) != 0) + if (wait_for_completion_interruptible(&queue->push)) flush_signals(current); } @@ -146,7 +146,7 @@ VCHIQ_HEADER_T *vchiu_queue_pop(VCHIU_QUEUE_T *queue) queue->read++; - up(&queue->pop); + complete(&queue->pop); return header; } diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h index 5a1540d349d3..b226227fe5bc 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.h @@ -35,7 +35,7 @@ #define VCHIQ_UTIL_H #include <linux/types.h> -#include <linux/semaphore.h> +#include <linux/completion.h> #include <linux/mutex.h> #include <linux/bitops.h> #include <linux/kthread.h> @@ -60,8 +60,8 @@ typedef struct { int write; int initialized; - struct semaphore pop; - struct semaphore push; + struct completion pop; + struct completion push; VCHIQ_HEADER_T **storage; } VCHIU_QUEUE_T; -- 2.19.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
