[Xen-devel] ns16550 polling timeout sanity check

[Alex Williamson <alex.williamson@xxxxxx>]

Hi Keir,

   Here's a small sanity check fix for the recently added ns16550
polling support.  If a device has a 1 byte tx fifo it's not hard for the
integer math to end up with a 0 timeout.  Default to a 1ms timeout if
this happens.  Thanks,

        Alex

Signed-off-by: Alex Williamson <alex.williamson@xxxxxx>
---

diff -r f5b119533cc8 xen/drivers/char/ns16550.c
--- a/xen/drivers/char/ns16550.c        Thu Dec  1 14:22:22 2005
+++ b/xen/drivers/char/ns16550.c        Thu Dec  1 09:28:48 2005
@@ -212,6 +212,8 @@
         /* Polled mode. Calculate time to fill RX FIFO and/or empty TX FIFO. */
         bits = uart->data_bits + uart->stop_bits + !!uart->parity;
         uart->timeout_ms = (bits * port->tx_fifo_size * 1000) / uart->baud;
+        if (!uart->timeout_ms)
+            uart->timeout_ms = 1;
         init_ac_timer(&uart->timer, ns16550_poll, port, 0);
         set_ac_timer(&uart->timer, NOW() + MILLISECS(uart->timeout_ms));
     }



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