[alsa-devel] snd_mixart_send_msg / snd_mixart_send_msg_wait_notif

[Rene Herman]

Hi.

While looking through ALSA for schedule_timeout() calls, I ran into:

int snd_mixart_send_msg(...)
{

	[ ... ]

         set_current_state(TASK_UNINTERRUPTIBLE);
         add_wait_queue(&mgr->msg_sleep, &wait);
         spin_unlock_irq(&mgr->msg_lock);
         timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
         remove_wait_queue(&mgr->msg_sleep, &wait);

         if (! timeout) {
                 /* error - no ack */
                 mutex_unlock(&mgr->msg_mutex);
                 snd_printk(KERN_ERR "error: no reponse on msg %x\n", 
msg_frame);
                 return -EIO;
         }

	[ ... ]

}

and the same in snd_mixart_send_msg_wait_notif().

I believe there to be  something wrong with this code. A schedule_timeout() 
in TASK_UNINTERRUPTIBLE is always going to return 0. Didn't you intend to 
use a wait_event_timeout() or something like that? Puzzled, since you err 
out on !timeout, and it seems every run through this would end up there.

Rene.