diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S
index e6f80fcf013bbbf16a30d7dd804c4b181685e15a..a4acddad0c78e84aa64055ca0cff7cc650cae720 100644
--- a/arch/ia64/kernel/head.S
+++ b/arch/ia64/kernel/head.S
@@ -259,7 +259,7 @@ start_ap:
 	 * Switch into virtual mode:
 	 */
 	movl r16=(IA64_PSR_IT|IA64_PSR_IC|IA64_PSR_DT|IA64_PSR_RT|IA64_PSR_DFH|IA64_PSR_BN \
-		  |IA64_PSR_DI|IA64_PSR_AC)
+		  |IA64_PSR_DI)
 	;;
 	mov cr.ipsr=r16
 	movl r17=1f
diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S
index 689ffcaa284e4ddbdbe1503b12d0713c7cb5c017..18e794a572489d7b308f7a779991d9c05351c463 100644
--- a/arch/ia64/kernel/ivt.S
+++ b/arch/ia64/kernel/ivt.S
@@ -58,7 +58,7 @@
 #include <asm/unistd.h>
 #include <asm/errno.h>
 
-#if 1
+#if 0
 # define PSR_DEFAULT_BITS	psr.ac
 #else
 # define PSR_DEFAULT_BITS	0
diff --git a/arch/ia64/kvm/vmm_ivt.S b/arch/ia64/kvm/vmm_ivt.S
index 24018484c6e93391060e0157540d804867bb6f58..397e34a63e188ea2a17953e5cbb20589356d0f2d 100644
--- a/arch/ia64/kvm/vmm_ivt.S
+++ b/arch/ia64/kvm/vmm_ivt.S
@@ -64,7 +64,7 @@
 #include "kvm_minstate.h"
 #include "vti.h"
 
-#if 1
+#if 0
 # define PSR_DEFAULT_BITS   psr.ac
 #else
 # define PSR_DEFAULT_BITS   0