usb: serial: mos7840: Fixup mos7840_chars_in_buffer()

commit 5c263b92f828af6a8cf54041db45ceae5af8f2ab upstream.

 * Use the buffer content length as opposed to the total buffer size.  This can
   be a real problem when using the mos7840 as a usb serial-console as all
   kernel output is truncated during boot.

Signed-off-by: Mark Ferrell <mferrell@uplogix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 5c7d654..b150ed9 100644 (file)
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1191,9 +1191,12 @@ static int mos7840_chars_in_buffer(struct tty_struct *tty)
        }
 
        spin_lock_irqsave(&mos7840_port->pool_lock, flags);
-       for (i = 0; i < NUM_URBS; ++i)
-               if (mos7840_port->busy[i])
-                       chars += URB_TRANSFER_BUFFER_SIZE;
+       for (i = 0; i < NUM_URBS; ++i) {
+               if (mos7840_port->busy[i]) {
+                       struct urb *urb = mos7840_port->write_urb_pool[i];
+                       chars += urb->transfer_buffer_length;
+               }
+       }
        spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
        dbg("%s - returns %d", __func__, chars);
        return chars;