Re: [PATCH 1/4] iio: adc: ad7124: fix chip ID mismatch

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 31 Jul 2024 15:37:22 +0300
Dumitru Ceclan <mitrutzceclan@gmail.com> wrote:

> The ad7124_soft_reset() function has the assumption that the chip will
> assert the "power-on reset" bit in the STATUS register after a software
> reset without any delay. The POR bit =0 is used to check if the chip
> initialization is done.
> 
> A chip ID mismatch probe error appears intermittently when the probe
> continues too soon and the ID register does not contain the expected
> value.
> 
> Fix by adding a 200us delay after the software reset command is issued.
> 
> Fixes: b3af341bbd96 ("iio: adc: Add ad7124 support")
> Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
Applied to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

J
> ---
>  drivers/iio/adc/ad7124.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
> index e7b1d517d3de..54d4c5597696 100644
> --- a/drivers/iio/adc/ad7124.c
> +++ b/drivers/iio/adc/ad7124.c
> @@ -762,6 +762,7 @@ static int ad7124_soft_reset(struct ad7124_state *st)
>  	if (ret < 0)
>  		return ret;
>  
> +	fsleep(200);
>  	timeout = 100;
>  	do {
>  		ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval);
>