On Wed, Nov 16, 2016 at 04:23:53PM -0600, Matt Weber wrote: > From: Jared Bents <[email protected]> > > Converts the unsigned temperature values from the i2c read > to be sign extended as defined in the datasheet so that > negative temperatures are properly read. > > Signed-off-by: Jared Bents <[email protected]> > Signed-off-by: Matt Weber <[email protected]> > --- > drivers/hwmon/amc6821.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c > index 12e851a..d7368f7 100644 > --- a/drivers/hwmon/amc6821.c > +++ b/drivers/hwmon/amc6821.c > @@ -188,7 +188,7 @@ static struct amc6821_data *amc6821_update_device(struct > device *dev) > !data->valid) { > > for (i = 0; i < TEMP_IDX_LEN; i++) > - data->temp[i] = i2c_smbus_read_byte_data(client, > + data->temp[i] = (int8_t) > i2c_smbus_read_byte_data(client,
How does that fix anything ? The only difference is that errors reported from i2c_smbus_read_byte_data() are now capped off and stored as 0xff and no longer as negative numbers. I don't see how a value of 0xff read from the chip would now be reported as -1 degrees C; it should be reported as 255 degrees C as it was all along. What am I missing here ? A real fix would be to actually check for errors either here or in the show function (temp[] < 0 indicates a transfer error), and to use sign_extend() to convert the 8-bit reading to a signed value. Guenter > temp_reg[i]); > > data->stat1 = i2c_smbus_read_byte_data(client, > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
