Intel D2500CC serial ports

[Robert Ames]

I just picked up an Intel D2500CCE motherboard and was disappointed
to find the serial ports didn't work.  There has been discussion
about this problem here:

http://lists.freebsd.org/pipermail/freebsd-current/2013-April/040897.html
http://lists.freebsd.org/pipermail/freebsd-current/2013-May/042088.html

As seen in the second link, Juergen Weiss was able to work around
the problem.  This patch (for 8.4-RELEASE amd64) makes all 4 serial
ports functional.

--- /usr/src/sys/amd64/amd64/io_apic.c.orig 2013-06-02 13:23:05.000000000 -0500
+++ /usr/src/sys/amd64/amd64/io_apic.c      2013-06-28 18:52:03.000000000 -0500
@@ -452,6 +452,10 @@
        KASSERT(!(trig == INTR_TRIGGER_CONFORM || pol == INTR_POLARITY_CONFORM),
            ("%s: Conforming trigger or polarity\n", __func__));
 
+       if (trig == INTR_TRIGGER_EDGE && pol == INTR_POLARITY_LOW) {
+               pol = INTR_POLARITY_HIGH;
+       }
+
        /*
         * EISA interrupts always use active high polarity, so don't allow
         * them to be set to active low.

However this is just a work around and not a general solution.  Does
anyone have suggestions on a fix that could be committed so the
serial ports for this board will work out of the box?