diff --git a/drivers/acpi/acpica/acutils.h b/drivers/acpi/acpica/acutils.h
index 7a568c6..83b75e9 100644
--- a/drivers/acpi/acpica/acutils.h
+++ b/drivers/acpi/acpica/acutils.h
@@ -211,6 +211,8 @@ acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr);
 
 acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr);
 
+char acpi_ut_remove_whitespace(char **string);
+
 char acpi_ut_remove_leading_zeros(char **string);
 
 u8 acpi_ut_detect_hex_prefix(char **string);
diff --git a/drivers/acpi/acpica/utstrsuppt.c b/drivers/acpi/acpica/utstrsuppt.c
index e402cf7..bec2b8e 100644
--- a/drivers/acpi/acpica/utstrsuppt.c
+++ b/drivers/acpi/acpica/utstrsuppt.c
@@ -231,6 +231,31 @@ char acpi_ut_remove_leading_zeros(char **string)
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ut_remove_whitespace
+ *
+ * PARAMETERS:  string                  - Pointer to input ASCII string
+ *
+ * RETURN:      Next character after any whitespace. This character may be
+ *              used by the caller to detect end-of-string.
+ *
+ * DESCRIPTION: Remove any leading whitespace in the input string. Return the
+ *              next character after the final ASCII zero to enable the caller
+ *              to check for the end of the string (NULL terminator).
+ *
+ ******************************************************************************/
+
+char acpi_ut_remove_whitespace(char **string)
+{
+
+	while (isspace((u8)**string)) {
+		*string += 1;
+	}
+
+	return (**string);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_ut_detect_hex_prefix
  *
  * PARAMETERS:  string                  - Pointer to input ASCII string
diff --git a/drivers/acpi/acpica/utstrtoul64.c b/drivers/acpi/acpica/utstrtoul64.c
index 67a39d9..e2067dc 100644
--- a/drivers/acpi/acpica/utstrtoul64.c
+++ b/drivers/acpi/acpica/utstrtoul64.c
@@ -66,22 +66,25 @@ ACPI_MODULE_NAME("utstrtoul64")
  *  iASL        - Main parser, conversion of constants to integers
  *  iASL        - Data Table Compiler parser (constants and math expressions)
  *  interpreter - Implicit and explicit conversions, GPE method names
+ *  interpreter - Repair code for return values from predefined names
  *  debugger    - Command line input string conversion
- *  acpi_dump   - Input table addresses
- *  acpi_exec   - Testing of the acpi_ut_strtoul64 function
+ *  acpi_dump   - ACPI table physical addresses
+ *  acpi_exec   - Support for namespace overrides
  *
  * Notes concerning users of these interfaces:
  *
- *  acpi_gbl_integer_byte_width is used to set the 32/64 bit limit. This global
- *  must be set to the proper width. For the core ACPICA code, the width
- *  depends on the DSDT version. For iASL, the default width is 64 bits for
- *  all parsers, but error checking is performed later to flag cases where
- *  a 64-bit constant is wrongly defined in a 32-bit DSDT/SSDT.
+ * acpi_gbl_integer_byte_width is used to set the 32/64 bit limit for explicit
+ * and implicit conversions. This global must be set to the proper width.
+ * For the core ACPICA code, the width depends on the DSDT version. For the
+ * acpi_ut_strtoul64 interface, all conversions are 64 bits. This interface is
+ * used primarily for iASL, where the default width is 64 bits for all parsers,
+ * but error checking is performed later to flag cases where a 64-bit constant
+ * is wrongly defined in a 32-bit DSDT/SSDT.
  *
- *  In ACPI, the only place where octal numbers are supported is within
- *  the ASL language itself. This is implemented via the main acpi_ut_strtoul64
- *  interface. According the ACPI specification, there is no ACPI runtime
- *  support for octal string conversions.
+ * In ACPI, the only place where octal numbers are supported is within
+ * the ASL language itself. This is implemented via the main acpi_ut_strtoul64
+ * interface. According the ACPI specification, there is no ACPI runtime
+ * support (explicit/implicit) for octal string conversions.
  *
  ******************************************************************************/
 /*******************************************************************************
@@ -93,11 +96,11 @@ ACPI_MODULE_NAME("utstrtoul64")
  *              return_value            - Where the converted integer is
  *                                        returned. Must be a valid pointer
  *
- * RETURN:      Status and converted integer
- *              Returns an exception on numeric overflow
+ * RETURN:      Status and converted integer. Returns an exception on a
+ *              64-bit numeric overflow
  *
- * DESCRIPTION: Convert a string into an unsigned integer. Performs either a
- *              32-bit or 64-bit conversion, depending on the current global
+ * DESCRIPTION: Convert a string into an unsigned integer. Always performs a
+ *              full 64-bit conversion, regardless of the current global
  *              integer width. Supports Decimal, Hex, and Octal strings.
  *
  * Current users of this function:
@@ -105,11 +108,15 @@ ACPI_MODULE_NAME("utstrtoul64")
  *  iASL        - Preprocessor (constants and math expressions)
  *  iASL        - Main ASL parser, conversion of ASL constants to integers
  *  iASL        - Data Table Compiler parser (constants and math expressions)
+ *  interpreter - Repair code for return values from predefined names
+ *  acpi_dump   - ACPI table physical addresses
+ *  acpi_exec   - Support for namespace overrides
  *
  ******************************************************************************/
 acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
 {
 	acpi_status status = AE_OK;
+	u8 original_bit_width;
 	u32 base = 10;		/* Default is decimal */
 
 	ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string);
@@ -122,6 +129,10 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
 		return_ACPI_STATUS(AE_OK);
 	}
 
+	if (!acpi_ut_remove_whitespace(&string)) {
+		return_ACPI_STATUS(AE_OK);
+	}
+
 	/*
 	 * 1) Check for a hex constant. A "0x" prefix indicates base 16.
 	 */
@@ -142,8 +153,16 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
 	}
 
 	/*
-	 * Perform the base 8, 10, or 16 conversion. A numeric overflow will
-	 * return an exception (to allow iASL to flag the statement).
+	 * Force a full 64-bit conversion. The caller (usually iASL) must
+	 * check for a 32-bit overflow later as necessary (If current mode
+	 * is 32-bit, meaning a 32-bit DSDT).
+	 */
+	original_bit_width = acpi_gbl_integer_bit_width;
+	acpi_gbl_integer_bit_width = 64;
+
+	/*
+	 * Perform the base 8, 10, or 16 conversion. A 64-bit numeric overflow
+	 * will return an exception (to allow iASL to flag the statement).
 	 */
 	switch (base) {
 	case 8:
@@ -160,6 +179,9 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
 		break;
 	}
 
+	/* Only possible exception from above is a 64-bit overflow */
+
+	acpi_gbl_integer_bit_width = original_bit_width;
 	return_ACPI_STATUS(status);
 }
 
@@ -223,6 +245,10 @@ u64 acpi_ut_implicit_strtoul64(char *string)
 
 	ACPI_FUNCTION_TRACE_STR(ut_implicit_strtoul64, string);
 
+	if (!acpi_ut_remove_whitespace(&string)) {
+		return_VALUE(0);
+	}
+
 	/*
 	 * Per the ACPI specification, only hexadecimal is supported for
 	 * implicit conversions, and the "0x" prefix is "not allowed".
@@ -236,8 +262,8 @@ u64 acpi_ut_implicit_strtoul64(char *string)
 
 	/*
 	 * Ignore overflow as per the ACPI specification. This is implemented by
-	 * ignoring the return status below. On overflow, the input string is
-	 * simply truncated.
+	 * ignoring the return status from the conversion function called below.
+	 * On overflow, the input string is simply truncated.
 	 */
 	acpi_ut_convert_hex_string(string, &converted_integer);
 	return_VALUE(converted_integer);
@@ -301,6 +327,10 @@ u64 acpi_ut_explicit_strtoul64(char *string)
 
 	ACPI_FUNCTION_TRACE_STR(ut_explicit_strtoul64, string);
 
+	if (!acpi_ut_remove_whitespace(&string)) {
+		return_VALUE(0);
+	}
+
 	/*
 	 * Only Hex and Decimal are supported, as per the ACPI specification.
 	 * A "0x" prefix indicates hex; otherwise decimal is assumed.
@@ -315,8 +345,8 @@ u64 acpi_ut_explicit_strtoul64(char *string)
 
 	/*
 	 * Ignore overflow as per the ACPI specification. This is implemented by
-	 * ignoring the return status below. On overflow, the input string is
-	 * simply truncated.
+	 * ignoring the return status from the conversion functions called below.
+	 * On overflow, the input string is simply truncated.
 	 */
 	switch (base) {
 	case 10:
