The CRC calculation always happens on 8 words which is why there is an extra element in the prom array of struct ms_tp_dev. However, on ms5637 and similar, only 7 words are readable. Then, set MS_SENSORS_TP_PROM_WORDS_NB to 8 and stop passing a len parameter to ms_sensors_tp_crc_valid as this simply hide the fact that it is hardcoded. Finally, use the newly introduced hw->prom_len to know how many words can be read. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210109231148.1168104-5-alexandre.belloni@bootlin.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>