- spin_lock(&acm->read_lock);
- list_add_tail(&rcv->list, &acm->spare_read_urbs);
- list_add_tail(&buf->list, &acm->filled_read_bufs);
- spin_unlock(&acm->read_lock);
-
+ if (likely(status == 0)) {
+ spin_lock(&acm->read_lock);
+ list_add_tail(&rcv->list, &acm->spare_read_urbs);
+ list_add_tail(&buf->list, &acm->filled_read_bufs);
+ spin_unlock(&acm->read_lock);
+ } else {
+ /* we drop the buffer due to an error */
+ spin_lock(&acm->read_lock);
+ list_add_tail(&rcv->list, &acm->spare_read_urbs);
+ list_add(&buf->list, &acm->spare_read_bufs);
+ spin_unlock(&acm->read_lock);
+ /* nevertheless the tasklet must be kicked unconditionally
+ so the queue cannot dry up */
+ }