--- 2.4.14/drivers/char/tty_io.c.orig	Thu Dec  6 00:07:23 2001
+++ 2.4.14/drivers/char/tty_io.c	Thu Dec  6 00:09:41 2001
@@ -697,8 +697,13 @@
 {
 	ssize_t ret = 0, written = 0;
 	
-	if (down_interruptible(&tty->atomic_write)) {
-		return -ERESTARTSYS;
+	if (file->f_flags & O_NONBLOCK) {
+		if (down_trylock(&tty->atomic_write))
+			return -EAGAIN;
+	}
+	else {
+		if (down_interruptible(&tty->atomic_write))
+			return -ERESTARTSYS;
 	}
 	if ( test_bit(TTY_NO_WRITE_SPLIT, &tty->flags) ) {
 		lock_kernel();