Re: ACPI/Interrupt trouble on AMD 880G

[buhrow%lothlorien.nfbcal.org@localhost (Brian Buhrow)]

        Hello.  I've had a long standing problem with interupt routing issues
and ACPI on my dell D400 laptop.  Does this patch work for you?  (This is
from mail I wrote in December 2007.)

From: buhrow%lothlorien.nfbcal.org@localhost (Brian Buhrow)
Date: Thu, 13 Dec 2007 22:56:33 -0800
Subject: A fix for ACPI BIOS's which route interrupts, but don't report their 
work -- was: Re: Problems with ath(4) and interrupt sharing

        Hello.  Well, it turns out that there isn't a fix in the BIOS for this
problem, but I was able to whip up a quick patch which I've submitted as
kern/37538, which allows me to use both the sound and wireless cards at
full speed with ACPI enabled.  
        The problem is that while the BIOS properly routes the interrupt for
these two devices, it doesn't actually report that the interrupt is valid
for these devices in its table.  So, when NetBSD tries to verify the
verasity of the interrupts, it can't, and so it tries to reroute the
interrupts to other irq's, with less than satisfactory results.  With this
patch, you can add
options ACPI_BELIEVE_BIOS
to your kernel config, and the kernel will just assume that what the BIOS
says is true is accurate with respect to irq assignments.
        I am by no means an ACPI expert, so if there's abetter way to achieve
this result, I'm all for it.  However, if not, then I'd like to see this
patch incorporated into the tree for NetBSD-4 and beyond, sinceI've
verified that the problem persists all the way through today's -current
sources.
        The complete bug report is available on the bug query web page, but
I'll include the patch below, since it's so short.

Comments?
-thanks
-Brian

Index: acpi_pci_link.c
===================================================================
RCS file: /cvsroot/src/sys/dev/acpi/acpi_pci_link.c,v
retrieving revision 1.7
diff -u -r1.7 acpi_pci_link.c
--- acpi_pci_link.c     24 Sep 2006 06:03:20 -0000      1.7
+++ acpi_pci_link.c     14 Dec 2007 06:03:25 -0000
@@ -369,6 +369,17 @@
 {
        int i;
 
+#ifdef ACPI_BELIEVE_BIOS
+       /*
+        *Some BIOS's route the interrupts correctly for the devices
+        *they configure, but don't report that those interrupts are valid in
+        *their interrupt table.  If this option is true, assume the BIOS
+        *did the right thing, and always return valid.
+        *Fixes interrupt problems with ACPI and the Dell D400 laptop
+        */
+       return(TRUE);
+#endif
+
        /* Invalid interrupts are never valid. */
        if (!PCI_INTERRUPT_VALID(irq))
                return (FALSE);