1 files changed, 11 insertions, 13 deletions

diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
index 046c4d0394ee..81473a4880ce 100644
--- a/drivers/acpi/acpica/tbfadt.c
+++ b/drivers/acpi/acpica/tbfadt.c
@@ -311,6 +311,8 @@ void acpi_tb_parse_fadt(void)
 {
 	u32 length;
 	struct acpi_table_header *table;
+	struct acpi_table_desc *fadt_desc;
+	acpi_status status;
 
 	/*
 	 * The FADT has multiple versions with different lengths,
@@ -319,14 +321,12 @@ void acpi_tb_parse_fadt(void)
 	 * Get a local copy of the FADT and convert it to a common format
 	 * Map entire FADT, assumed to be smaller than one page.
 	 */
-	length = acpi_gbl_root_table_list.tables[acpi_gbl_fadt_index].length;
-
-	table =
-	    acpi_os_map_memory(acpi_gbl_root_table_list.
-			       tables[acpi_gbl_fadt_index].address, length);
-	if (!table) {
+	fadt_desc = &acpi_gbl_root_table_list.tables[acpi_gbl_fadt_index];
+	status = acpi_tb_get_table(fadt_desc, &table);
+	if (ACPI_FAILURE(status)) {
 		return;
 	}
+	length = fadt_desc->length;
 
 	/*
 	 * Validate the FADT checksum before we copy the table. Ignore
@@ -340,7 +340,7 @@ void acpi_tb_parse_fadt(void)
 
 	/* All done with the real FADT, unmap it */
 
-	acpi_os_unmap_memory(table, length);
+	acpi_tb_put_table(fadt_desc);
 
 	/* Obtain the DSDT and FACS tables via their addresses within the FADT */
 
@@ -480,19 +480,17 @@ static void acpi_tb_convert_fadt(void)
 	u32 i;
 
 	/*
-	 * For ACPI 1.0 FADTs (revision 1), ensure that reserved fields which
+	 * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
 	 * should be zero are indeed zero. This will workaround BIOSs that
 	 * inadvertently place values in these fields.
 	 *
 	 * The ACPI 1.0 reserved fields that will be zeroed are the bytes located
 	 * at offset 45, 55, 95, and the word located at offset 109, 110.
 	 *
-	 * Note: The FADT revision value is unreliable because of BIOS errors.
-	 * The table length is instead used as the final word on the version.
-	 *
-	 * Note: FADT revision 3 is the ACPI 2.0 version of the FADT.
+	 * Note: The FADT revision value is unreliable. Only the length can be
+	 * trusted.
 	 */
-	if (acpi_gbl_FADT.header.length <= ACPI_FADT_V3_SIZE) {
+	if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) {
 		acpi_gbl_FADT.preferred_profile = 0;
 		acpi_gbl_FADT.pstate_control = 0;
 		acpi_gbl_FADT.cst_control = 0;