ACPI: Work around IASL warning reading/writing same register

The newer versions of IASL are unhappy when an operator
has the same object as both source and destination.

The warning can be completely disabled with a command
line argument, but in general, I'd really rather not
just disable warnings.

The bits in this register are write 1 to clear, so reading and
writing the same register is what we want to do.  Instead, store
it in a temporary register then write it in a second operation.

Fixes warning:
dsdt.aml   1396:  Store(PWST, PWST)
Warning  3023 -                 ^ Duplicate value in list
(Source is the same as Target)

Change-Id: I52d73d4431db237be83016d67cd397f31b53d9c6
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/12691
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

36 files changed, 73 insertions, 36 deletions

diff --git a/src/mainboard/advansus/a785e-i/dsdt.asl b/src/mainboard/advansus/a785e-i/dsdt.asl
index 652b3663e0..03fc82da5f 100644
--- a/src/mainboard/advansus/a785e-i/dsdt.asl
+++ b/src/mainboard/advansus/a785e-i/dsdt.asl
@@ -931,7 +931,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/bimini_fam10/dsdt.asl b/src/mainboard/amd/bimini_fam10/dsdt.asl
index 3d5d2e3339..ec1e60e983 100644
--- a/src/mainboard/amd/bimini_fam10/dsdt.asl
+++ b/src/mainboard/amd/bimini_fam10/dsdt.asl
@@ -931,7 +931,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/dbm690t/dsdt.asl b/src/mainboard/amd/dbm690t/dsdt.asl
index 3f5c1925c0..46d3671576 100644
--- a/src/mainboard/amd/dbm690t/dsdt.asl
+++ b/src/mainboard/amd/dbm690t/dsdt.asl
@@ -898,7 +898,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/inagua/acpi/sleep.asl b/src/mainboard/amd/inagua/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/amd/inagua/acpi/sleep.asl
+++ b/src/mainboard/amd/inagua/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/mahogany/dsdt.asl b/src/mainboard/amd/mahogany/dsdt.asl
index 7623f76fdb..5602368760 100644
--- a/src/mainboard/amd/mahogany/dsdt.asl
+++ b/src/mainboard/amd/mahogany/dsdt.asl
@@ -895,7 +895,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/mahogany_fam10/dsdt.asl b/src/mainboard/amd/mahogany_fam10/dsdt.asl
index 2fe6a56ac5..afc3823a6f 100644
--- a/src/mainboard/amd/mahogany_fam10/dsdt.asl
+++ b/src/mainboard/amd/mahogany_fam10/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/persimmon/acpi/sleep.asl b/src/mainboard/amd/persimmon/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/amd/persimmon/acpi/sleep.asl
+++ b/src/mainboard/amd/persimmon/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/pistachio/dsdt.asl b/src/mainboard/amd/pistachio/dsdt.asl
index 69d28be4e9..6322289c07 100644
--- a/src/mainboard/amd/pistachio/dsdt.asl
+++ b/src/mainboard/amd/pistachio/dsdt.asl
@@ -897,7 +897,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/south_station/acpi/sleep.asl b/src/mainboard/amd/south_station/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/amd/south_station/acpi/sleep.asl
+++ b/src/mainboard/amd/south_station/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/tilapia_fam10/dsdt.asl b/src/mainboard/amd/tilapia_fam10/dsdt.asl
index f85cb59ee1..daf912dc50 100644
--- a/src/mainboard/amd/tilapia_fam10/dsdt.asl
+++ b/src/mainboard/amd/tilapia_fam10/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/amd/union_station/acpi/sleep.asl b/src/mainboard/amd/union_station/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/amd/union_station/acpi/sleep.asl
+++ b/src/mainboard/amd/union_station/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/asrock/e350m1/acpi/sleep.asl b/src/mainboard/asrock/e350m1/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/asrock/e350m1/acpi/sleep.asl
+++ b/src/mainboard/asrock/e350m1/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/asus/kgpe-d16/acpi/pm_ctrl.asl b/src/mainboard/asus/kgpe-d16/acpi/pm_ctrl.asl
index c9bc0a99c1..b5a7ed9ba2 100644
--- a/src/mainboard/asus/kgpe-d16/acpi/pm_ctrl.asl
+++ b/src/mainboard/asus/kgpe-d16/acpi/pm_ctrl.asl
@@ -256,7 +256,8 @@ Method(\_WAK, 1) {
 
 	/* Configure southbridge for wake */
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	Store (0x22, DBG8)
 
diff --git a/src/mainboard/asus/m4a78-em/dsdt.asl b/src/mainboard/asus/m4a78-em/dsdt.asl
index 3d82d25ea7..28c8c4ab73 100644
--- a/src/mainboard/asus/m4a78-em/dsdt.asl
+++ b/src/mainboard/asus/m4a78-em/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/asus/m4a785-m/dsdt.asl b/src/mainboard/asus/m4a785-m/dsdt.asl
index 3d82d25ea7..28c8c4ab73 100644
--- a/src/mainboard/asus/m4a785-m/dsdt.asl
+++ b/src/mainboard/asus/m4a785-m/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/asus/m4a785t-m/dsdt.asl b/src/mainboard/asus/m4a785t-m/dsdt.asl
index 07bf4014c3..6adb8cabfa 100644
--- a/src/mainboard/asus/m4a785t-m/dsdt.asl
+++ b/src/mainboard/asus/m4a785t-m/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/asus/m5a88-v/dsdt.asl b/src/mainboard/asus/m5a88-v/dsdt.asl
index 04042bdb37..f9a17589e0 100644
--- a/src/mainboard/asus/m5a88-v/dsdt.asl
+++ b/src/mainboard/asus/m5a88-v/dsdt.asl
@@ -931,7 +931,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/avalue/eax-785e/dsdt.asl b/src/mainboard/avalue/eax-785e/dsdt.asl
index 9476a3e5c5..fd29b80451 100644
--- a/src/mainboard/avalue/eax-785e/dsdt.asl
+++ b/src/mainboard/avalue/eax-785e/dsdt.asl
@@ -931,7 +931,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/gigabyte/ma785gm/dsdt.asl b/src/mainboard/gigabyte/ma785gm/dsdt.asl
index b1ff955510..091d08ef40 100644
--- a/src/mainboard/gigabyte/ma785gm/dsdt.asl
+++ b/src/mainboard/gigabyte/ma785gm/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/gigabyte/ma785gmt/dsdt.asl b/src/mainboard/gigabyte/ma785gmt/dsdt.asl
index b1ff955510..091d08ef40 100644
--- a/src/mainboard/gigabyte/ma785gmt/dsdt.asl
+++ b/src/mainboard/gigabyte/ma785gmt/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/gigabyte/ma78gm/dsdt.asl b/src/mainboard/gigabyte/ma78gm/dsdt.asl
index b1ff955510..091d08ef40 100644
--- a/src/mainboard/gigabyte/ma78gm/dsdt.asl
+++ b/src/mainboard/gigabyte/ma78gm/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/gizmosphere/gizmo/acpi/sleep.asl b/src/mainboard/gizmosphere/gizmo/acpi/sleep.asl
index 3c33defd4c..bb68f7a3d4 100644
--- a/src/mainboard/gizmosphere/gizmo/acpi/sleep.asl
+++ b/src/mainboard/gizmosphere/gizmo/acpi/sleep.asl
@@ -105,7 +105,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/iei/kino-780am2-fam10/dsdt.asl b/src/mainboard/iei/kino-780am2-fam10/dsdt.asl
index ec303bd336..09ce655ad2 100644
--- a/src/mainboard/iei/kino-780am2-fam10/dsdt.asl
+++ b/src/mainboard/iei/kino-780am2-fam10/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/jetway/nf81-t56n-lf/acpi/sleep.asl b/src/mainboard/jetway/nf81-t56n-lf/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/jetway/nf81-t56n-lf/acpi/sleep.asl
+++ b/src/mainboard/jetway/nf81-t56n-lf/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/jetway/pa78vm5/dsdt.asl b/src/mainboard/jetway/pa78vm5/dsdt.asl
index eae9bbeab2..507ef3ba40 100644
--- a/src/mainboard/jetway/pa78vm5/dsdt.asl
+++ b/src/mainboard/jetway/pa78vm5/dsdt.asl
@@ -937,7 +937,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/kontron/kt690/dsdt.asl b/src/mainboard/kontron/kt690/dsdt.asl
index bfe63f79ee..5884e74a55 100644
--- a/src/mainboard/kontron/kt690/dsdt.asl
+++ b/src/mainboard/kontron/kt690/dsdt.asl
@@ -898,7 +898,9 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
+
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/lippert/frontrunner-af/dsdt.asl b/src/mainboard/lippert/frontrunner-af/dsdt.asl
index eaac89517b..9e3b39c840 100644
--- a/src/mainboard/lippert/frontrunner-af/dsdt.asl
+++ b/src/mainboard/lippert/frontrunner-af/dsdt.asl
@@ -925,7 +925,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/lippert/toucan-af/dsdt.asl b/src/mainboard/lippert/toucan-af/dsdt.asl
index a9a7485436..8623aae04c 100644
--- a/src/mainboard/lippert/toucan-af/dsdt.asl
+++ b/src/mainboard/lippert/toucan-af/dsdt.asl
@@ -925,7 +925,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/pcengines/apu1/acpi/sleep.asl b/src/mainboard/pcengines/apu1/acpi/sleep.asl
index e043ee211b..b3fd07ef00 100644
--- a/src/mainboard/pcengines/apu1/acpi/sleep.asl
+++ b/src/mainboard/pcengines/apu1/acpi/sleep.asl
@@ -104,7 +104,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/siemens/sitemp_g1p1/acpi/event.asl b/src/mainboard/siemens/sitemp_g1p1/acpi/event.asl
index b3697711f6..c2ac98cd65 100644
--- a/src/mainboard/siemens/sitemp_g1p1/acpi/event.asl
+++ b/src/mainboard/siemens/sitemp_g1p1/acpi/event.asl
@@ -140,7 +140,8 @@ Method(\_WAK, 1) {
 	}
 
 	/* Arbitrarily clear PciExpWakeStatus */
-	Store(PWST, PWST)
+	Store(PWST, Local1)
+	Store(Local1, PWST)
 
 	/* if(DeRefOf(Index(WKST,0))) {
 	*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/supermicro/h8qgi/dsdt.asl b/src/mainboard/supermicro/h8qgi/dsdt.asl
index e488bab766..8395c7b26b 100644
--- a/src/mainboard/supermicro/h8qgi/dsdt.asl
+++ b/src/mainboard/supermicro/h8qgi/dsdt.asl
@@ -970,7 +970,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/supermicro/h8scm/dsdt.asl b/src/mainboard/supermicro/h8scm/dsdt.asl
index 78f927cb13..84788b8c70 100644
--- a/src/mainboard/supermicro/h8scm/dsdt.asl
+++ b/src/mainboard/supermicro/h8scm/dsdt.asl
@@ -970,7 +970,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/supermicro/h8scm_fam10/dsdt.asl b/src/mainboard/supermicro/h8scm_fam10/dsdt.asl
index 8f5daea02a..dfe10769d8 100644
--- a/src/mainboard/supermicro/h8scm_fam10/dsdt.asl
+++ b/src/mainboard/supermicro/h8scm_fam10/dsdt.asl
@@ -955,7 +955,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/technexion/tim5690/dsdt.asl b/src/mainboard/technexion/tim5690/dsdt.asl
index f45f8f3b7c..a763bcfe0e 100644
--- a/src/mainboard/technexion/tim5690/dsdt.asl
+++ b/src/mainboard/technexion/tim5690/dsdt.asl
@@ -898,7 +898,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/technexion/tim8690/dsdt.asl b/src/mainboard/technexion/tim8690/dsdt.asl
index d0ce009e62..692c02b72d 100644
--- a/src/mainboard/technexion/tim8690/dsdt.asl
+++ b/src/mainboard/technexion/tim8690/dsdt.asl
@@ -898,7 +898,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))
diff --git a/src/mainboard/tyan/s8226/dsdt.asl b/src/mainboard/tyan/s8226/dsdt.asl
index f15d8bb2aa..015687e215 100644
--- a/src/mainboard/tyan/s8226/dsdt.asl
+++ b/src/mainboard/tyan/s8226/dsdt.asl
@@ -970,7 +970,8 @@ DefinitionBlock (
 		}
 
 		/* Arbitrarily clear PciExpWakeStatus */
-		Store(PWST, PWST)
+		Store(PWST, Local1)
+		Store(Local1, PWST)
 
 		/* if(DeRefOf(Index(WKST,0))) {
 		*	Store(0, Index(WKST,1))