LinuxDevice: fixed reboot.

- Deal with the dropped connection on issuing "reboot"
- Introduced a fixed initial delay before polling for connection to
  avoid re-connecting to adevice that is still in the process of
  shutting down.

wlauto/common/linux/device.py

@@ -632,7 +632,11 @@ class LinuxDevice(BaseLinuxDevice):
     # Power control
 
     def reset(self):
-        self.execute('reboot', as_root=True)
+        try:
+            self.execute('reboot', as_root=True)
+        except DeviceError as e:
+            if 'Connection dropped' not in e.message:
+                raise e
         self._is_ready = False
 
     def hard_reset(self):
@@ -644,8 +648,15 @@ class LinuxDevice(BaseLinuxDevice):
         else:
             self.reset()
         self.logger.debug('Waiting for device...')
+        # Wait a fixed delay before starting polling to give the device time to
+        # shut down, otherwise, might create the connection while it's still shutting
+        # down resulting in subsequenct connection failing.
+        initial_delay = 20
+        time.sleep(initial_delay)
+        boot_timeout = max(self.boot_timeout - initial_delay, 10)
+
         start_time = time.time()
-        while (time.time() - start_time) < self.boot_timeout:
+        while (time.time() - start_time) < boot_timeout:
             try:
                 s = socket.create_connection((self.host, self.port), timeout=5)
                 s.close()

wlauto/utils/ssh.py

@@ -172,9 +172,8 @@ class SshShell(object):
                         logger.warning('Could not get exit code for "{}",\ngot: "{}"'.format(command, exit_code_text))
                 return output
         except EOF:
-            logger.error('Dropped connection detected.')
             self.connection_lost = True
-            raise
+            raise DeviceError('Connection dropped.')
 
     def logout(self):
         logger.debug('Logging out {}@{}'.format(self.username, self.host))