ACPI / hotplug: Generate online uevents for ACPI containers

Commit 46394fd01 (ACPI / hotplug: Move container-specific code out of
the core) removed the generation of "online" uevents for containers,
because "add" uevents are now generated for them automatically when
container system devices are registered.  However, there are user
space tools that need to be notified when the container and all of
its children have been enumerated, which doesn't happen any more.

For this reason, add a mechanism allowing "online" uevents to be
generated for ACPI containers after enumerating the container along
with all of its children.

Fixes: 46394fd01 (ACPI / hotplug: Move container-specific code out of the core)
Reported-and-tested-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 12 insertions, 0 deletions

diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c
index 76f7cff64594..c8ead9f97375 100644
--- a/drivers/acpi/container.c
+++ b/drivers/acpi/container.c
@@ -99,6 +99,13 @@ static void container_device_detach(struct acpi_device *adev)
                 device_unregister(dev);
 }
 
+static void container_device_online(struct acpi_device *adev)
+{
+        struct device *dev = acpi_driver_data(adev);
+
+        kobject_uevent(&dev->kobj, KOBJ_ONLINE);
+}
+
 static struct acpi_scan_handler container_handler = {
         .ids = container_device_ids,
         .attach = container_device_attach,
@@ -106,6 +113,7 @@ static struct acpi_scan_handler container_handler = {
         .hotplug = {
                 .enabled = true,
                 .demand_offline = true,
+                .notify_online = container_device_online,
         },
 };
 
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 3bf7764659a4..1c9a664c1705 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2189,6 +2189,9 @@ static void acpi_bus_attach(struct acpi_device *device)
  ok:
         list_for_each_entry(child, &device->children, node)
                 acpi_bus_attach(child);
+
+        if (device->handler && device->handler->hotplug.notify_online)
+                device->handler->hotplug.notify_online(device);
 }
 
 /**
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index c1c9de19edbe..2f98cf84368f 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -118,6 +118,7 @@ struct acpi_device;
 struct acpi_hotplug_profile {
         struct kobject kobj;
         int (*scan_dependent)(struct acpi_device *adev);
+        void (*notify_online)(struct acpi_device *adev);
         bool enabled:1;
         bool demand_offline:1;
 };