diff --git a/drivers/base/sync.c b/drivers/base/sync.c index 326e184a9bbdc2f909be9ed3b98fc74c840de3f4..4c5689ba56cebad1b5e7fd0bf1d020b4be6374b5 100644 --- a/drivers/base/sync.c +++ b/drivers/base/sync.c @@ -556,6 +556,16 @@ int sync_fence_cancel_async(struct sync_fence *fence, } EXPORT_SYMBOL(sync_fence_cancel_async); +static bool sync_fence_check(struct sync_fence *fence) +{ + /* + * Make sure that reads to fence->status are ordered with the + * wait queue event triggering + */ + smp_rmb(); + return fence->status != 0; +} + int sync_fence_wait(struct sync_fence *fence, long timeout) { int err = 0; @@ -563,7 +573,7 @@ int sync_fence_wait(struct sync_fence *fence, long timeout) if (timeout > 0) { timeout = msecs_to_jiffies(timeout); err = wait_event_interruptible_timeout(fence->wq, - fence->status != 0, + sync_fence_check(fence), timeout); } else if (timeout < 0) { err = wait_event_interruptible(fence->wq, fence->status != 0); @@ -627,6 +637,12 @@ static unsigned int sync_fence_poll(struct file *file, poll_table *wait) poll_wait(file, &fence->wq, wait); + /* + * Make sure that reads to fence->status are ordered with the + * wait queue event triggering + */ + smp_rmb(); + if (fence->status == 1) return POLLIN; else if (fence->status < 0)