ACPICA: Fix parameter validation for acpi_read/write

Now return AE_BAD_PARAMETER if the input register pointer is
null, and AE_BAD_ADDRESS if the register has an address of zero.
Previously, these cases simply returned AE_OK. For optional
registers such as PM1B status/enable/control, the caller should
check for a valid register address before calling.  ACPICA BZ 748.

http://www.acpica.org/bugzilla/show_bug.cgi?id=748

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/hwxface.c

@@ -107,19 +107,18 @@ acpi_status acpi_read(u32 *value, struct acpi_generic_address *reg)
 	ACPI_FUNCTION_NAME(acpi_read);
 
 	/*
-	 * Must have a valid pointer to a GAS structure, and
-	 * a non-zero address within. However, don't return an error
-	 * because the PM1A/B code must not fail if B isn't present.
+	 * Must have a valid pointer to a GAS structure, and a non-zero address
+	 * within.
 	 */
 	if (!reg) {
-		return (AE_OK);
+		return (AE_BAD_PARAMETER);
 	}
 
 	/* Get a local copy of the address. Handles possible alignment issues */
 
 	ACPI_MOVE_64_TO_64(&address, &reg->address);
 	if (!address) {
-		return (AE_OK);
+		return (AE_BAD_ADDRESS);
 	}
 
 	/* Supported widths are 8/16/32 */
@@ -187,19 +186,18 @@ acpi_status acpi_write(u32 value, struct acpi_generic_address *reg)
 	ACPI_FUNCTION_NAME(acpi_write);
 
 	/*
-	 * Must have a valid pointer to a GAS structure, and
-	 * a non-zero address within. However, don't return an error
-	 * because the PM1A/B code must not fail if B isn't present.
+	 * Must have a valid pointer to a GAS structure, and a non-zero address
+	 * within.
 	 */
 	if (!reg) {
-		return (AE_OK);
+		return (AE_BAD_PARAMETER);
 	}
 
 	/* Get a local copy of the address. Handles possible alignment issues */
 
 	ACPI_MOVE_64_TO_64(&address, &reg->address);
 	if (!address) {
-		return (AE_OK);
+		return (AE_BAD_ADDRESS);
 	}
 
 	/* Supported widths are 8/16/32 */