# HG changeset patch
# User Akshat Kumar <seed@mail.nanosouffle.net>
# Date 1326919609 28800
# Node ID ad15087848d427a3480da063cd6fe905302e31ad
# Parent  731d41fbe3944407ff5d96f2987bc25bbc21f993
devacpi: bogus xdsdt in ACPI table

A bogus xdsdt address in the ACPI table seemed
to be rendering my system unbootable. Using the
dsdt seems to have resolved the issue. In the
general case, I have followed the ACPICA: match
the 32-bit address with the 64-bit address, and
prefer the 32-bit address. Unlike facs vs. xfacs
(where one is necessarily 0), the ACPI spec sheet
(4.0a) does not specify what happens between
dsdt vs xdsdt. This case seems to show that in
implementation, it is not necessary that one is 0.

R=nix-dev, nemo, john
CC=nix-dev
http://codereview.appspot.com/5556048

Committer: John Floren <john@jfloren.net>

diff -r 731d41fbe394 -r ad15087848d4 sys/src/nix/k10/devacpi.c
--- a/sys/src/nix/k10/devacpi.c	Tue Jan 17 13:33:37 2012 -0800
+++ b/sys/src/nix/k10/devacpi.c	Wed Jan 18 12:46:49 2012 -0800
@@ -609,7 +609,8 @@
 		loadfacs(fp->xfacs);
 	else
 		loadfacs(fp->facs);
-	if(fp->xdsdt != 0)
+
+	if(fp->xdsdt == ((u64int)fp->dsdt)) /* acpica */
 		loaddsdt(fp->xdsdt);
 	else
 		loaddsdt(fp->dsdt);