Pull bugzilla-8346 into release branch

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/acpi/tables/tbfadt.c b/drivers/acpi/tables/tbfadt.c
index 807c7116e94b..1db833eb2417 100644
--- a/drivers/acpi/tables/tbfadt.c
+++ b/drivers/acpi/tables/tbfadt.c
@@ -347,6 +347,18 @@ static void acpi_tb_convert_fadt(void)
                 acpi_gbl_xpm1b_enable.space_id = acpi_gbl_FADT.xpm1a_event_block.space_id;
 
         }
+
+        /*
+         * For ACPI 1.0 FADTs, ensure that reserved fields (which should be zero)
+         * are indeed zero. This will workaround BIOSs that inadvertently placed
+         * values in these fields.
+         */
+        if (acpi_gbl_FADT.header.revision < 3) {
+                acpi_gbl_FADT.preferred_profile = 0;
+                acpi_gbl_FADT.pstate_control = 0;
+                acpi_gbl_FADT.cst_control = 0;
+                acpi_gbl_FADT.boot_flags = 0;
+        }
 }
 
 /******************************************************************************