3 files changed, 68 insertions, 79 deletions

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 809b8082c134..a0d42cf5b0c5 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -89,7 +89,7 @@ void acpi_device_add_finalize(struct acpi_device *device);
 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);
 int acpi_bind_one(struct device *dev, acpi_handle handle);
 int acpi_unbind_one(struct device *dev);
-void acpi_bus_device_eject(void *data, u32 ost_src);
+void acpi_device_hotplug(void *data, u32 ost_src);
 bool acpi_device_is_present(struct acpi_device *adev);
 
 /* --------------------------------------------------------------------------
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 4076491c6ded..ca05064f3ff7 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -683,11 +683,13 @@ static void hotplug_event_root(void *data, u32 type)
                 if (!root)
                         break;
 
+                acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
+                                          ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
                 get_device(&root->device->dev);
 
                 acpi_scan_lock_release();
 
-                acpi_bus_device_eject(root->device, ACPI_NOTIFY_EJECT_REQUEST);
+                acpi_device_hotplug(root->device, ACPI_NOTIFY_EJECT_REQUEST);
                 return;
         default:
                 acpi_handle_warn(handle,
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 4fa416f94f52..dd0ff9de9277 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -206,12 +206,8 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
         acpi_status status;
         unsigned long long sta;
 
-        /* If there is no handle, the device node has been unregistered. */
-        if (!handle) {
-                dev_dbg(&device->dev, "ACPI handle missing\n");
-                put_device(&device->dev);
-                return -EINVAL;
-        }
+        if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
+                kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 
         /*
          * Carry out two passes here and ignore errors in the first pass,
@@ -230,7 +226,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
                 dev_warn(errdev, "Offline disabled.\n");
                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                                     acpi_bus_online, NULL, NULL, NULL);
-                put_device(&device->dev);
                 return -EPERM;
         }
         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
@@ -249,7 +244,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
                                             ACPI_UINT32_MAX, acpi_bus_online,
                                             NULL, NULL, NULL);
-                        put_device(&device->dev);
                         return -EBUSY;
                 }
         }
@@ -259,9 +253,6 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
 
         acpi_bus_trim(device);
 
-        put_device(&device->dev);
-        device = NULL;
-
         acpi_evaluate_lck(handle, 0);
         /*
          * TBD: _EJD support.
@@ -288,77 +279,74 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
         return 0;
 }
 
-void acpi_bus_device_eject(void *data, u32 ost_src)
+static int acpi_scan_device_check(struct acpi_device *adev)
 {
-        struct acpi_device *device = data;
-        acpi_handle handle = device->handle;
-        u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
         int error;
 
-        lock_device_hotplug();
-        mutex_lock(&acpi_scan_lock);
-
-        if (ost_src == ACPI_NOTIFY_EJECT_REQUEST)
-                acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
-                                          ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
-
-        if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
-                kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
-
-        error = acpi_scan_hot_remove(device);
-        if (error == -EPERM) {
-                goto err_support;
-        } else if (error) {
-                goto err_out;
+        /*
+         * This function is only called for device objects for which matching
+         * scan handlers exist.  The only situation in which the scan handler is
+         * not attached to this device object yet is when the device has just
+         * appeared (either it wasn't present at all before or it was removed
+         * and then added again).
+         */
+        if (adev->handler) {
+                dev_warn(&adev->dev, "Already enumerated\n");
+                return -EBUSY;
         }
-
- out:
-        mutex_unlock(&acpi_scan_lock);
-        unlock_device_hotplug();
-        return;
-
- err_support:
-        ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
- err_out:
-        acpi_evaluate_hotplug_ost(handle, ost_src, ost_code, NULL);
-        goto out;
+        error = acpi_bus_scan(adev->handle);
+        if (error) {
+                dev_warn(&adev->dev, "Namespace scan failure\n");
+                return error;
+        }
+        if (adev->handler) {
+                if (adev->handler->hotplug.mode == AHM_CONTAINER)
+                        kobject_uevent(&adev->dev.kobj, KOBJ_ONLINE);
+        } else {
+                dev_warn(&adev->dev, "Enumeration failure\n");
+                return -ENODEV;
+        }
+        return 0;
 }
 
-static void acpi_scan_bus_device_check(void *data, u32 ost_source)
+void acpi_device_hotplug(void *data, u32 src)
 {
-        acpi_handle handle = data;
-        struct acpi_device *device;
         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
+        struct acpi_device *adev = data;
         int error;
 
         lock_device_hotplug();
         mutex_lock(&acpi_scan_lock);
 
-        if (ost_source != ACPI_NOTIFY_BUS_CHECK) {
-                device = NULL;
-                acpi_bus_get_device(handle, &device);
-                if (acpi_device_enumerated(device)) {
-                        dev_warn(&device->dev, "Attempt to re-insert\n");
-                        goto out;
-                }
-        }
-        error = acpi_bus_scan(handle);
-        if (error) {
-                acpi_handle_warn(handle, "Namespace scan failure\n");
-                goto out;
-        }
-        device = NULL;
-        acpi_bus_get_device(handle, &device);
-        if (!acpi_device_enumerated(device)) {
-                acpi_handle_warn(handle, "Device not enumerated\n");
+        /*
+         * The device object's ACPI handle cannot become invalid as long as we
+         * are holding acpi_scan_lock, but it may have become invalid before
+         * that lock was acquired.
+         */
+        if (adev->handle == INVALID_ACPI_HANDLE)
                 goto out;
+
+        switch (src) {
+        case ACPI_NOTIFY_BUS_CHECK:
+                error = acpi_bus_scan(adev->handle);
+                break;
+        case ACPI_NOTIFY_DEVICE_CHECK:
+                error = acpi_scan_device_check(adev);
+                break;
+        case ACPI_NOTIFY_EJECT_REQUEST:
+        case ACPI_OST_EC_OSPM_EJECT:
+                error = acpi_scan_hot_remove(adev);
+                break;
+        default:
+                error = -EINVAL;
+                break;
         }
-        ost_code = ACPI_OST_SC_SUCCESS;
-        if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
-                kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
+        if (!error)
+                ost_code = ACPI_OST_SC_SUCCESS;
 
  out:
-        acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
+        acpi_evaluate_hotplug_ost(adev->handle, src, ost_code, NULL);
+        put_device(&adev->dev);
         mutex_unlock(&acpi_scan_lock);
         unlock_device_hotplug();
 }
@@ -370,6 +358,9 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
         struct acpi_device *adev;
         acpi_status status;
 
+        if (acpi_bus_get_device(handle, &adev))
+                goto err_out;
+
         switch (type) {
         case ACPI_NOTIFY_BUS_CHECK:
                 acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
@@ -384,24 +375,20 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
                         goto err_out;
                 }
-                if (acpi_bus_get_device(handle, &adev))
-                        goto err_out;
-
-                get_device(&adev->dev);
-                status = acpi_hotplug_execute(acpi_bus_device_eject, adev, type);
-                if (ACPI_SUCCESS(status))
-                        return;
-
-                put_device(&adev->dev);
-                goto err_out;
+                acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
+                                          ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
+                break;
         default:
                 /* non-hotplug event; possibly handled by other handler */
                 return;
         }
-        status = acpi_hotplug_execute(acpi_scan_bus_device_check, handle, type);
+        get_device(&adev->dev);
+        status = acpi_hotplug_execute(acpi_device_hotplug, adev, type);
         if (ACPI_SUCCESS(status))
                 return;
 
+        put_device(&adev->dev);
+
  err_out:
         acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 }
@@ -454,7 +441,7 @@ acpi_eject_store(struct device *d, struct device_attribute *attr,
         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
         get_device(&acpi_device->dev);
-        status = acpi_hotplug_execute(acpi_bus_device_eject, acpi_device,
+        status = acpi_hotplug_execute(acpi_device_hotplug, acpi_device,
                                       ACPI_OST_EC_OSPM_EJECT);
         if (ACPI_SUCCESS(status))
                 return count;