1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 4877cdbc58cc..15721a776cd4 100644
--- 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;
 }