ACPICA: Update for ACPI 5 hardware-reduced feature

Ensure that AcpiEnable and AcpiDisable work properly when the
hardware-reduced flag is set in the FADT.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/hwacpi.c b/drivers/acpi/acpica/hwacpi.c
index deb3f61e2bd1..9b02a9f5b04a 100644
--- a/drivers/acpi/acpica/hwacpi.c
+++ b/drivers/acpi/acpica/hwacpi.c
@@ -66,6 +66,12 @@ acpi_status acpi_hw_set_mode(u32 mode)
 
         ACPI_FUNCTION_TRACE(hw_set_mode);
 
+        /* If the Hardware Reduced flag is set, machine is always in acpi mode */
+
+        if (acpi_gbl_reduced_hardware) {
+                return_ACPI_STATUS(AE_OK);
+        }
+
         /*
          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
          * system does not support mode transition.
@@ -146,6 +152,12 @@ u32 acpi_hw_get_mode(void)
 
         ACPI_FUNCTION_TRACE(hw_get_mode);
 
+        /* If the Hardware Reduced flag is set, machine is always in acpi mode */
+
+        if (acpi_gbl_reduced_hardware) {
+                return_VALUE(ACPI_SYS_MODE_ACPI);
+        }
+
         /*
          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
          * system does not support mode transition.