Rearrange the code to pull the operations beore the fence->lock critical section, and remove a small amount of redundancy:
Function old new delta dma_fence_add_callback 156 145 -11
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk --- drivers/dma-buf/dma-fence.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 656e9ac2d028..8d5bdfce638e 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -348,29 +348,25 @@ EXPORT_SYMBOL(dma_fence_enable_sw_signaling); int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb, dma_fence_func_t func) { - unsigned long flags; - int ret = 0; + int ret = -ENOENT;
if (WARN_ON(!fence || !func)) return -EINVAL;
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { - INIT_LIST_HEAD(&cb->node); - return -ENOENT; - } + cb->func = func; + INIT_LIST_HEAD(&cb->node);
- spin_lock_irqsave(fence->lock, flags); + if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { + unsigned long flags;
- if (__dma_fence_enable_signaling(fence)) { - cb->func = func; - list_add_tail(&cb->node, &fence->cb_list); - } else { - INIT_LIST_HEAD(&cb->node); - ret = -ENOENT; + spin_lock_irqsave(fence->lock, flags); + if (__dma_fence_enable_signaling(fence)) { + list_add_tail(&cb->node, &fence->cb_list); + ret = 0; + } + spin_unlock_irqrestore(fence->lock, flags); }
- spin_unlock_irqrestore(fence->lock, flags); - return ret; } EXPORT_SYMBOL(dma_fence_add_callback);