Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (27 commits)
  ACPI: Don't let acpi_pad needlessly mark TSC unstable
  drivers/acpi/sleep.h: Checkpatch cleanup
  ACPI: Minor cleanup eliminating redundant PMTIMER_TICKS to NS conversion
  ACPI: delete unused c-state promotion/demotion data strucutures
  ACPI: video: fix acpi_backlight=video
  ACPI: EC: Use kmemdup
  drivers/acpi: use kasprintf
  ACPI, APEI, EINJ injection parameters support
  Add x64 support to debugfs
  ACPI, APEI, Use ERST for persistent storage of MCE
  ACPI, APEI, Error Record Serialization Table (ERST) support
  ACPI, APEI, Generic Hardware Error Source memory error support
  ACPI, APEI, UEFI Common Platform Error Record (CPER) header
  Unified UUID/GUID definition
  ACPI Hardware Error Device (PNP0C33) support
  ACPI, APEI, PCIE AER, use general HEST table parsing in AER firmware_first setup
  ACPI, APEI, Document for APEI
  ACPI, APEI, EINJ support
  ACPI, APEI, HEST table parsing
  ACPI, APEI, APEI supporting infrastructure
  ...

1 files changed, 21 insertions, 12 deletions

diff --git a/drivers/acpi/acpica/evxfevnt.c b/drivers/acpi/acpica/evxfevnt.c
index 7c7bbb4d402c..d5a5efc043bf 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)