On Mon, Jun 20, 2022 at 01:23:39AM +0200, Andy Shevchenko wrote: > On Sun, Jun 19, 2022 at 8:58 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > > Vincent: I'm getting some instability with roadtest after forwards porting to > > current mainline. Tests run 'sometimes'. Other times I get a crash > > in um_set_signal. Seems unrelated to the test this series adds. > > > > Changes since v1: Thanks to Andy and Peter for reviews. > > - Use sizeof(data) for be24 buffer data[3] > > - Make the precision patch fall back to old maths if overflow would > > have occured. > > > > This started out as an experiment with Vincent Whitchurch's roadtest > > testing framework [1] and that worked well so I carried on cleaning up the > > driver. > > > > Mostly this is standard tidy up, move to new interfaces, then move the driver > > out of staging, but there are a few other things in here. > > > > 1) Precision improvement for IIO_VAL_FRACTIONAL_LOG2. > > The ad7746 is a 24 bit sensor and this highlighted that 9 decimal > > places wasn't enough to keep the error introduced by > > _raw * _scale from growing too large over the whole range (I couldn't > > write a sensible test for it). So I've proposed increasing the precision > > of the calculation used to provide the sysfs attributes with this value > > type and printing a few more decimal places (12), but only if overflow > > will not occur due to val[0] > ULLONG_MAX / PICO > > 2) _inputoffset ABI addition. This driver had an odd use of _offset for > > the case of differential channels that applied the offset to both > > of the differential pair (hence usespace shouldn't not apply it when > > userspace? > Also, there's a confusing double negative. Either "should" or "should not". Thanks, Joe
