Add a little section about ACPI, explaining that disabling ACPI might help

troubleshooting interrupt problems on some machines, and insist people
should report such problems or they'll never get fixed. Final commit to
the installation notes for this release.
ok deraadt@

1 files changed, 26 insertions, 1 deletions

diff --git a/distrib/notes/amd64/hardware b/distrib/notes/amd64/hardware
index 341d9f93d90..e8184089dc5 100644
--- a/distrib/notes/amd64/hardware
+++ b/distrib/notes/amd64/hardware
@@ -1,4 +1,4 @@
-dnl	$OpenBSD: hardware,v 1.92 2008/08/05 23:03:05 miod Exp $
+dnl	$OpenBSD: hardware,v 1.93 2008/08/07 06:18:42 miod Exp $
 OpenBSD/MACHINE OSREV should work on all Athlon 64-based and
 compatible designs.
 
@@ -1403,3 +1403,28 @@ dnl		XR16850-based ports (only in the pccom driver)
 		    Winbond W83627HF, W83627THF, W83627DHG, W83627EHF, W83637HF
 		    Winbond W83697HF, W83781D, W83782D, W83783S, W83791D, W83792D
 		    Winbond W83793G
+
+ACPI notice:
+
+	OpenBSD supports the ACPI information provided by many modern
+	machine BIOSes.  On a minority of systems, this ACPI information
+	may be misleading or misinterpreted.
+
+	This might cause various drivers to misbehave in more or less
+	fatal ways, most problems being interrupt-related (interrupt
+	storms slowing the machine down, or a device not getting any
+	interrupts at all).
+
+	If your system seems to misbehave under OpenBSD, you might want
+	to try booting the kernel with ACPI support disabled.
+
+	To do so, boot with the -c flag at the initial bootloader prompt.
+	After the kernel loads, at the UKC> prompt, enter "disable acpi"
+	followed by "quit". This will disable ACPI support.
+
+	If disabling ACPI helps, it is possible to make this behaviour
+	permanent with the userland config(8) utility. In any case,
+	please open a bug report with sendbug(1), giving as many
+	details as possible, including the dmesg(8) output for both ACPI
+	and ACPI-disabled kernels, as well as the output from acpidump(8)
+	and pcidump(8).