1 files changed, 21 insertions, 12 deletions

diff --git a/drivers/acpi/acpica/evxfevnt.c b/drivers/acpi/acpica/evxfevnt.c
index 5ff32c78ea2d..bfbe291d572e 100644
--- a/drivers/acpi/acpica/evxfevnt.c
+++ b/drivers/acpi/acpica/evxfevnt.c
@@ -69,7 +69,7 @@ acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
 
 acpi_status acpi_enable(void)
 {
-        acpi_status status = AE_OK;
+        acpi_status status;
 
         ACPI_FUNCTION_TRACE(acpi_enable);
 
@@ -84,21 +84,30 @@ acpi_status acpi_enable(void)
         if (acpi_hw_get_mode() == ACPI_SYS_MODE_ACPI) {
                 ACPI_DEBUG_PRINT((ACPI_DB_INIT,
                                   "System is already in ACPI mode\n"));
-        } else {
-                /* Transition to ACPI mode */
+                return_ACPI_STATUS(AE_OK);
+        }
 
-                status = acpi_hw_set_mode(ACPI_SYS_MODE_ACPI);
-                if (ACPI_FAILURE(status)) {
-                        ACPI_ERROR((AE_INFO,
-                                    "Could not transition to ACPI mode"));
-                        return_ACPI_STATUS(status);
-                }
+        /* Transition to ACPI mode */
 
-                ACPI_DEBUG_PRINT((ACPI_DB_INIT,
-                                  "Transition to ACPI mode successful\n"));
+        status = acpi_hw_set_mode(ACPI_SYS_MODE_ACPI);
+        if (ACPI_FAILURE(status)) {
+                ACPI_ERROR((AE_INFO,
+                            "Could not transition to ACPI mode"));
+                return_ACPI_STATUS(status);
         }
 
-        return_ACPI_STATUS(status);
+        /* Sanity check that transition succeeded */
+
+        if (acpi_hw_get_mode() != ACPI_SYS_MODE_ACPI) {
+                ACPI_ERROR((AE_INFO,
+                            "Hardware did not enter ACPI mode"));
+                return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
+        }
+
+        ACPI_DEBUG_PRINT((ACPI_DB_INIT,
+                          "Transition to ACPI mode successful\n"));
+
+        return_ACPI_STATUS(AE_OK);
 }
 
 ACPI_EXPORT_SYMBOL(acpi_enable)