cleaned up

Reference: /n/patches.lsub.org/patch/acpifixes
Date: Mon May 21 12:16:04 CES 2012
Signed-off-by: paurea@lsub.org

--- /sys/src/nix/k10/devacpi.c	Thu Apr 12 12:26:27 2012
+++ /sys/src/nix/k10/devacpi.c	Mon May 21 11:54:40 2012
@@ -17,7 +17,6 @@
  * for the user-level interpreter.
  */
 
-
 #define l16get(p)	(((p)[1]<<8)|(p)[0])
 #define l32get(p)	(((u32int)l16get(p+2)<<16)|l16get(p))
 static Atable* acpifadt(uchar*, int);
@@ -558,6 +557,7 @@
 	Fadt *fp;
 
 	fp = &fadt;
+	DBG("acpifadt %p\n", p);
 	fp->facs = l32get(p + 36);
 	fp->dsdt = l32get(p + 40);
 	fp->pmprofile = p[45];
@@ -595,6 +595,7 @@
 	fp->iapcbootarch = l16get(p+109);
 	fp->flags = l32get(p+112);
 	gasget(&fp->resetreg, p+116);
+
 	fp->resetval = p[128];
 	fp->xfacs = l64get(p+132);
 	fp->xdsdt = l64get(p+140);
@@ -608,15 +609,24 @@
 	gasget(&fp->xgpe1blk, p+232);
 
 	dumpfadt(fp);
-	if(fp->xfacs != 0)
+
+	/* If xfacs or xdsdt are either nil
+	 * or different from their 32-bit
+	 * counter-parts, then go with
+	 * the 32-bit addresses (as the
+	 * ACPICA does), since those are
+	 * tested by BIOS manufacturers.
+	 */
+
+	if(fp->xfacs != 0 && fp->xfacs == fp->facs)
 		loadfacs(fp->xfacs);
 	else
 		loadfacs(fp->facs);
 
-	if(fp->xdsdt == ((u64int)fp->dsdt)) /* acpica */
-		loaddsdt(fp->xdsdt);
+	if(fp->xdsdt != 0 && fp->xdsdt == fp->dsdt)
+		loadfacs(fp->xdsdt);
 	else
-		loaddsdt(fp->dsdt);
+		loadfacs(fp->dsdt);
 
 	return nil;	/* can be unmapped once parsed */
 }