ACPI: Verify device status after eject

ACPI spec states that the OS evaluates _STA after calling _EJ0
in order to verify if eject was successful.  Added a check to
verify if the enabled bit of the status value is cleared after
_EJ0.

Note, the present bit is not checked since some FW implementations
do not clear the present bit until the hardware is physically
removed.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index dfdbcfdd9def..8cacc16af6e7 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -127,6 +127,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
         struct acpi_object_list arg_list;
         union acpi_object arg;
         acpi_status status;
+        unsigned long long sta;
 
         /* If there is no handle, the device node has been unregistered. */
         if (!handle) {
@@ -164,10 +165,25 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
                 if (status == AE_NOT_FOUND) {
                         return -ENODEV;
                 } else {
-                        acpi_handle_warn(handle, "Eject failed\n");
+                        acpi_handle_warn(handle, "Eject failed (0x%x)\n",
+                                                                status);
                         return -EIO;
                 }
         }
+
+        /*
+         * Verify if eject was indeed successful.  If not, log an error
+         * message.  No need to call _OST since _EJ0 call was made OK.
+         */
+        status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+        if (ACPI_FAILURE(status)) {
+                acpi_handle_warn(handle,
+                        "Status check after eject failed (0x%x)\n", status);
+        } else if (sta & ACPI_STA_DEVICE_ENABLED) {
+                acpi_handle_warn(handle,
+                        "Eject incomplete - status 0x%llx\n", sta);
+        }
+
         return 0;
 }