On Tue, Aug 1, 2017 at 12:59 PM, Ladislav Michl <ladis@xxxxxxxxxxxxxx> wrote: > On Tue, Aug 01, 2017 at 12:09:34PM +0300, Daniel Baluta wrote: >> On Tue, Aug 1, 2017 at 11:26 AM, Ladislav Michl <ladis@xxxxxxxxxxxxxx> wrote: >> > When reading diffrent channel value than device is currently processing >> > wait time of conversion period is applied, which is not enough as device >> > might be already in the middle of conversion and therefore previously >> > converted value is returned - the one belonging to another channel. >> > Fix it by waiting for two sampling periods. >> > >> > Signed-off-by: Ladislav Michl <ladis@xxxxxxxxxxxxxx> >> >> Did you actually experienced this in practice? I guess you are right, >> if you change the channel during a conversion, this change will be applied >> to the next conversion *but* reading will still return old value because the >> current conversion hasn't finished yet. > > Yes, that's what actually happens without patch and could be easily > demonstrated from command line: > > $ cat in_voltage0_raw > 847 > $ cat in_voltage1_raw > 846 > $ cat in_voltage1_raw > 195 > $ cat in_voltage0_raw > 196 > $ cat in_voltage0_raw > 846 > > Btw, driver is using continuous conversion mode, but I was unable to > make iio_generic_buffer work with it. And for reading values one by > one single shot mode is enough. Any hints? Haven't looked at this sensor for long time. Can you tell us what have you tried and what doesn't work? Daniel. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
