1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/acpi/tables/tbfadt.c b/drivers/acpi/tables/tbfadt.c
index d2e60a8fa9a5..14661a861c58 100644
--- a/drivers/acpi/tables/tbfadt.c
+++ b/drivers/acpi/tables/tbfadt.c
@@ -286,14 +286,27 @@ static void acpi_tb_convert_fadt(void)
 
         acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
 
-        /* Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary */
-
+        /*
+         * Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary.
+         * Later code will always use the X 64-bit field. Also, check for an
+         * address mismatch between the 32-bit and 64-bit address fields
+         * (FIRMWARE_CTRL/X_FIRMWARE_CTRL, DSDT/X_DSDT) which would indicate
+         * the presence of two FACS or two DSDT tables.
+         */
         if (!acpi_gbl_FADT.Xfacs) {
                 acpi_gbl_FADT.Xfacs = (u64) acpi_gbl_FADT.facs;
+        } else if (acpi_gbl_FADT.facs &&
+                   (acpi_gbl_FADT.Xfacs != (u64) acpi_gbl_FADT.facs)) {
+                ACPI_WARNING((AE_INFO,
+                    "32/64 FACS address mismatch in FADT - two FACS tables!"));
         }
 
         if (!acpi_gbl_FADT.Xdsdt) {
                 acpi_gbl_FADT.Xdsdt = (u64) acpi_gbl_FADT.dsdt;
+        } else if (acpi_gbl_FADT.dsdt &&
+                   (acpi_gbl_FADT.Xdsdt != (u64) acpi_gbl_FADT.dsdt)) {
+                ACPI_WARNING((AE_INFO,
+                    "32/64 DSDT address mismatch in FADT - two DSDT tables!"));
         }
 
         /*