add_action( 'gform_user_registered', 'pi_gravity_registration_autologin', 10, 4 );
/**
 * Auto login after registration.
 */

function pi_gravity_registration_autologin( $user_id, $user_config, $entry, $password ) {
	$user = get_userdata( $user_id );
	$user_login = $user->user_login;
	$user_password = $password;

    wp_signon( array(
		'user_login' => $user_login,
		'user_password' =>  $user_password,
		'remember' => false
    ) );
}