diff -Nru linux/drivers/char/sb1250_duart.c.orig linux/drivers/char/sb1250_duart.c
--- linux/drivers/char/sb1250_duart.c.orig	Fri Nov 30 21:39:30 2001
+++ linux/drivers/char/sb1250_duart.c	Thu Dec 20 17:38:24 2001
@@ -370,10 +370,10 @@
 	duart_mask_ints(line, M_DUART_IMR_TX);
 	spin_lock_irqsave(&us->outp_lock, flags);
 	us->outp_head = us->outp_tail = us->outp_count = 0;
-	spin_unlock_irqrestore(&us->outp_lock, flags);
 	if (us->flags & SD_WRITE_WAKE) {
 		wake_up_interruptible(&us->tty->write_wait);
 	}	
+	spin_unlock_irqrestore(&us->outp_lock, flags);
 }