3 files changed, 38 insertions, 19 deletions

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 945cd2f2807d..e9b116d2b56d 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -112,21 +112,21 @@ int acpi_bus_get_status(struct acpi_device *device)
         }
 
         /*
-         * Otherwise we assume the status of our parent (unless we don't
-         * have one, in which case status is implied).
+         * According to ACPI spec some device can be present and functional
+         * even if the parent is not present but functional.
+         * In such conditions the child device should not inherit the status
+         * from the parent.
          */
-        else if (device->parent)
-                device->status = device->parent->status;
         else
                 STRUCT_TO_INT(device->status) =
                     ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
                     ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
 
         if (device->status.functional && !device->status.present) {
-                printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
-                       "functional but not present; setting present\n",
-                       device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
-                device->status.present = 1;
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
+                       "functional but not present;\n",
+                        device->pnp.bus_id,
+                        (u32) STRUCT_TO_INT(device->status)));
         }
 
         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index ad0679843bd5..89c112ef9e14 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -276,6 +276,13 @@ int acpi_match_device_ids(struct acpi_device *device,
 {
         const struct acpi_device_id *id;
 
+        /*
+         * If the device is not present, it is unnecessary to load device
+         * driver for it.
+         */
+        if (!device->status.present)
+                return -ENODEV;
+
         if (device->flags.hardware_id) {
                 for (id = ids; id->id[0]; id++) {
                         if (!strcmp((char*)id->id, device->pnp.hardware_id))
@@ -1222,15 +1229,18 @@ acpi_add_single_object(struct acpi_device **child,
                         result = -ENODEV;
                         goto end;
                 }
-                if (!device->status.present) {
-                        /* Bay and dock should be handled even if absent */
-                        if (!ACPI_SUCCESS(
-                             acpi_is_child_device(device, acpi_bay_match)) &&
-                            !ACPI_SUCCESS(
-                             acpi_is_child_device(device, acpi_dock_match))) {
-                                        result = -ENODEV;
-                                        goto end;
-                        }
+                /*
+                 * When the device is neither present nor functional, the
+                 * device should not be added to Linux ACPI device tree.
+                 * When the status of the device is not present but functinal,
+                 * it should be added to Linux ACPI tree. For example : bay
+                 * device , dock device.
+                 * In such conditions it is unncessary to check whether it is
+                 * bay device or dock device.
+                 */
+                if (!device->status.present && !device->status.functional) {
+                        result = -ENODEV;
+                        goto end;
                 }
                 break;
         default:
@@ -1411,7 +1421,12 @@ static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
                  * TBD: Need notifications and other detection mechanisms
                  *      in place before we can fully implement this.
                  */
-                if (child->status.present) {
+                 /*
+                 * When the device is not present but functional, it is also
+                 * necessary to scan the children of this device.
+                 */
+                if (child->status.present || (!child->status.present &&
+                                        child->status.functional)) {
                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
                                                       NULL, NULL);
                         if (ACPI_SUCCESS(status)) {
diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index c1b9ea34977b..98b9df7776e9 100644
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -148,9 +148,13 @@ static int __init pnpacpi_add_device(struct acpi_device *device)
         acpi_status status;
         struct pnp_dev *dev;
 
+        /*
+         * If a PnPacpi device is not present , the device
+         * driver should not be loaded.
+         */
         status = acpi_get_handle(device->handle, "_CRS", &temp);
         if (ACPI_FAILURE(status) || !ispnpidacpi(acpi_device_hid(device)) ||
-            is_exclusive_device(device))
+            is_exclusive_device(device) || (!device->status.present))
                 return 0;
 
         dev = pnp_alloc_dev(&pnpacpi_protocol, num, acpi_device_hid(device));