On 10/18/2018 02:55 PM, Dan Carpenter wrote: > On Thu, Oct 18, 2018 at 12:10:32PM +0300, Stefan Popa wrote: >> +static int ad7606_read_samples(struct ad7606_state *st) >> +{ >> + unsigned int num = st->chip_info->num_channels; >> + u16 *data = st->data; >> + int ret; >> + >> + /* >> + * The frstdata signal is set to high while and after reading the sample >> + * of the first channel and low for all other channels. This can be used >> + * to check that the incoming data is correctly aligned. During normal >> + * operation the data should never become unaligned, but some glitch or >> + * electrostatic discharge might cause an extra read or clock cycle. >> + * Monitoring the frstdata signal allows to recover from such failure >> + * situations. >> + */ >> + >> + if (st->gpio_frstdata) { >> + ret = st->bops->read_block(st->dev, 1, data); >> + if (ret) >> + return ret; >> + >> + if (!gpiod_get_value(st->gpio_frstdata)) { > > This check should maybe be: > > if (gpiod_get_value(st->gpio_frstdata) <= 0) { > > (Or possibly not, I don't know the code very well). gpiod_get_value() is only allowed to return either 0 or 1.