--- linux-2.4.4/drivers/usb/acm.c	Fri Feb 16 16:06:17 2001
+++ linux-2.4/drivers/usb/acm.c	Thu May 10 21:29:29 2001
@@ -233,8 +240,14 @@
 		dbg("nonzero read bulk status received: %d", urb->status);
 
 	if (!urb->status & !acm->throttle)  {
-		for (i = 0; i < urb->actual_length && !acm->throttle; i++)
+		for (i = 0; i < urb->actual_length && !acm->throttle; i++) {
+			/* if we insert more than TTY_FLIPBUF_SIZE characters, 
+			 * we drop them. */
+			if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
+				tty_flip_buffer_push(tty);
+			}
 			tty_insert_flip_char(tty, data[i], 0);
+		}
 		tty_flip_buffer_push(tty);
 	}