firewire: Grab dev->sem when doing the update callback.

This serializes the update callback with the probe and remove callback from
the driver core and prevents remove from being called while update is
running for the same device.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 4877cdbc58cca8e7b5757234e9de81c57dec21de..15721a776cd44e3dd52edf67c3c8ed8ee6294e1d 100644 (file)
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -562,8 +562,11 @@ static int update_unit(struct device *dev, void *data)
        struct fw_unit *unit = fw_unit(dev);
        struct fw_driver *driver = (struct fw_driver *)dev->driver;
 
-       if (is_fw_unit(dev) && driver != NULL && driver->update != NULL)
+       if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
+               down(&dev->sem);
                driver->update(unit);
+               up(&dev->sem);
+       }
 
        return 0;
 }