diff options
author | Nicolas Saenz Julienne <nsaenzjulienne@suse.de> | 2018-11-20 15:53:46 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-27 10:13:37 +0100 |
commit | f27e47bc6b8b96dd34ebad2a659b8a983cf367df (patch) | |
tree | e971496ef8ad21a0cbe475f212ae66850a157c85 /drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c | |
parent | staging: vchiq_core: don't add a wmb() before remote_event_signal() (diff) | |
download | linux-dev-f27e47bc6b8b96dd34ebad2a659b8a983cf367df.tar.xz linux-dev-f27e47bc6b8b96dd34ebad2a659b8a983cf367df.zip |
staging: vchiq: use completions instead of semaphores
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@suse.de>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c')
-rw-r--r-- | drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c | 16 |
1 files changed, 8 insertions, 8 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; } |