[PATCH] MdeModulePkg/Variable: Attribute combination should return EFI_UNSUPPORTED

["Stuart Yoder" <stuart.yoder@arm.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4341

Commit 21320ef66989 broke some tests in the AuthVar_Conf test
in edk2-test.  There are 2 testcases that invoke SetVariable
with the following attribute value:

(EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)

EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is deprecated and the UEFI spec
says this should return EFI_UNSUPPORTED.

Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Sunny Wang <Sunny.Wang@arm.com>

Signed-off-by: Stuart Yoder <stuart.yoder@arm.com>
---
 MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index 6c1a3440ac..14c176887a 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -2676,7 +2676,11 @@ VariableServiceSetVariable (
     //
     // Only EFI_VARIABLE_NON_VOLATILE attribute is invalid
     //
-    return EFI_INVALID_PARAMETER;
+    if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
+      return EFI_UNSUPPORTED;
+    } else {
+      return EFI_INVALID_PARAMETER;
+    }
   } else if ((Attributes & VARIABLE_ATTRIBUTE_AT_AW) != 0) {
     if (!mVariableModuleGlobal->VariableGlobal.AuthSupport) {
       //
-- 
2.34.1