From: "Ainux.Wang" <ainux.wang@xxxxxxxxx> There are some questions about PMBUS_STATUS in core. Signed-off-by: Ainux.Wang <ainux.wang@xxxxxxxxx> --- drivers/hwmon/pmbus/pmbus_core.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index bbd745178147..e16c85997148 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -2200,6 +2200,19 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data, * Some PMBus chips don't support PMBUS_STATUS_WORD, so try * to use PMBUS_STATUS_BYTE instead if that is the case. * Bail out if both registers are not supported. + * + * Question 1: + * Why bail out if both registers are not supported? + * MP2949A both registers are not supported. + * + * Question 2: + * Use i2c_smbus_read_word_data() or i2c_smbus_read_byte_data + * to read, the MP2949A will return undetermined value, although + * we already known this chip do not support both registers. + * What should we do? + * Can we use pmbus_read_status_byte() or pmbus_read_status_word()? + * and in MP2949A driver's .read_byte_data and .read_word_data to + * filter out both registers? */ data->read_status = pmbus_read_status_word; ret = i2c_smbus_read_word_data(client, PMBUS_STATUS_WORD); -- 2.18.1
