driver core: add BUS_NOTIFY_UNBOUND_DRIVER event

This patch adds a new bus notifier event which is emitted _after_ a
device is removed from its driver. This event will be used by the
dma-api debug code to check if a driver has released all dma allocations
for that device.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 742cbe6b042b..efd00de183b1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -320,6 +320,10 @@ static void __device_release_driver(struct device *dev)
                 devres_release_all(dev);
                 dev->driver = NULL;
                 klist_remove(&dev->p->knode_driver);
+                if (dev->bus)
+                        blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+                                                     BUS_NOTIFY_UNBOUND_DRIVER,
+                                                     dev);
         }
 }