def get_feature_report(self, report_id, length):
self._check_device_status()<EOL>bufp = ffi.new("<STR_LIT>", length+<NUM_LIT:1>)<EOL>buf = ffi.buffer(bufp, length+<NUM_LIT:1>)<EOL>buf[<NUM_LIT:0>] = report_id<EOL>rv = hidapi.hid_get_feature_report(self._device, bufp, length+<NUM_LIT:1>)<EOL>if rv == -<NUM_LIT:1>:<EOL><INDENT>raise IOError("<STR_LIT>"<EOL>.format(self._get_last_error_string()))<EOL><DEDENT>return buf[<NUM_LIT:1>:]<EOL>
Get a feature report from the device.

        :param report_id:   The Report ID of the report to be read
        :type report_id:    int
        :return:            The report data
        :rtype:             str/bytes