From e5ba06cbe80a02325184ffc9bc032e9794d963ae Mon Sep 17 00:00:00 2001
From: Junjie Mao <junjie.mao@intel.com>
Date: Fri, 6 Aug 2021 15:08:15 +0800
Subject: [PATCH] board_inspector: a workaround to an incorrect interpretation

The current design of AML parsing, objects are first defined in the
namespace and later dropped if they are in a False branch. This leads to
incorrect interpretation of the AML code where:

  1. A name T is defined in the root scope as an integer.

  2. A method M in an inner scope S references T.

  3. The name T is defined as a device, power resource or other named
     objects in scope S under conditions where M will not be called.

As a workaround, check if both the left and right hand sides are integers
first. If either is not the case,

Tracked-On: #6287
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
---
 .../acpiparser/aml/datatypes.py                |  4 +++-
 .../acpiparser/aml/interpreter.py              | 18 +++++++++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/misc/config_tools/board_inspector/acpiparser/aml/datatypes.py b/misc/config_tools/board_inspector/acpiparser/aml/datatypes.py
index 6b583c253..50ead0b92 100644
--- a/misc/config_tools/board_inspector/acpiparser/aml/datatypes.py
+++ b/misc/config_tools/board_inspector/acpiparser/aml/datatypes.py
@@ -399,7 +399,9 @@ class Package(Object):
     def to_string(self):
         return "Package"
 
-# PowerResource
+class PowerResource(Object):
+    def __init__(self, name):
+        self.name = name
 
 # Processor
 
diff --git a/misc/config_tools/board_inspector/acpiparser/aml/interpreter.py b/misc/config_tools/board_inspector/acpiparser/aml/interpreter.py
index 37d41c941..3c9d5d362 100644
--- a/misc/config_tools/board_inspector/acpiparser/aml/interpreter.py
+++ b/misc/config_tools/board_inspector/acpiparser/aml/interpreter.py
@@ -336,6 +336,9 @@ class ConcreteInterpreter(Interpreter):
         self.context.register_operation_region(sym.name, op_region)
         return op_region
 
+    def DefPowerRes(self, tree):
+        return PowerResource(tree.NameString.value)
+
     # 20.2.5.3 Statement Opcodes Encoding
     def DefBreak(self, tree):
         self.to_break = True
@@ -385,7 +388,20 @@ class ConcreteInterpreter(Interpreter):
     def __eval_binary_op(self, tree, op):
         lhs = self.interpret(tree.children[0])
         rhs = self.interpret(tree.children[1])
-        res = Integer(op(lhs.get(), rhs.get()))
+        # FIXME: The current design of AML parsing, objects are first defined in the namespace and later dropped if they
+        # are in a False branch. This leads to incorrect interpretation of the AML code where:
+        #
+        #   1. A name T is defined in the root scope as an integer.
+        #   2. A method M in an inner scope S references T.
+        #   3. The name T is defined as a device, power resource or other named objects in scope S under conditions
+        #      where M will not be called.
+        #
+        # As a workaround, check if both the left and right hand sides are integers first. If either is not the case,
+        # the condition is evaluated to False.
+        if isinstance(lhs, Integer) and isinstance(rhs, Integer):
+            res = Integer(op(lhs.get(), rhs.get()))
+        else:
+            res = Integer(0)
         if len(tree.children) >= 3:
             target = self.interpret(tree.children[2])
             if target: