Re: USB broken in 2.4.4? Serial Ricochet works, USB performance sucks.

[Greg KH]

On Thu, May 10, 2001 at 08:07:50PM -0700, Drew Bertola wrote:
> 
> Joey Hess had a problem similar to what you described, though he noticed
> it while using the pcmcia ricochet modem.  He passed along this patch:

Doh!  I've only fixed this same kind of problem about 3 different times
in the usb-serial drivers.  clameter, could you try the attached patch
against 2.4.4 and see if that fixes the MTU issue for you?

Thanks Drew for reminding me of this.

greg k-h


--- 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);
        }