wait_for_completion_timeout 超时返回0 的问题

"kernel/sched/core.c"

3419 /**
3420  * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
3421  * @x:  holds the state of this particular completion
3422  * @timeout:  timeout value in jiffies
3423  *
3424  * This waits for either a completion of a specific task to be signaled or for a
3425  * specified timeout to expire. The timeout is in jiffies. It is not
3426  * interruptible.
3427  *
3428  * The return value is 0 if timed out, and positive (at least 1, or number of
3429  * jiffies left till timeout) if completed.
3430  */
3431 unsigned long __sched
3432 wait_for_completion_timeout(struct completion *x, unsigned long timeout)
3433 {
3434         return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
3435 }
3436 EXPORT_SYMBOL(wait_for_completion_timeout);
3437

返回0 就是超时，我试试把time out 设置大一些看看是否会好点。