diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index ba1d025502..fcefdb7582 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -329,7 +329,8 @@ class Device(DeviceConfig, DevicePlugin):
                 return subprocess.Popen(cmd,
                                     stdout=subprocess.PIPE).communicate()[0]
             except IOError: # Probably an interrupted system call
-                pass
+                if i == 2:
+                    raise
             time.sleep(2)