diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index e2c33c06190bb1fa0975b634b765de70d22ad71f..8e25ca7080c7bb0a73ae3b3eb63ed79721d58d64 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -907,6 +907,7 @@ static ssize_t cosa_write(struct file *file,
 			current->state = TASK_RUNNING;
 			chan->tx_status = 1;
 			spin_unlock_irqrestore(&cosa->lock, flags);
+			up(&chan->wsem);
 			return -ERESTARTSYS;
 		}
 	}