On Wed, 16 Dec 2020 13:57:20 +0200
Slaveyko Slaveykov <sis@xxxxxxxxxxx> wrote:
> After an I2C reset command, the mlx90632 needs some time before
> responding to other I2C commands. Without that delay, there is a chance
> that the I2C command(s) after the reset will not be accepted.
>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Reviewed-by: Crt Mori <cmo@xxxxxxxxxxx>
> Signed-off-by: Slaveyko Slaveykov <sis@xxxxxxxxxxx>
Note that this should have had a fixes tag so we know where to apply it whilst
backporting. I took a look and ended up adding:
Fixes: e02472f74a81 ("iio:temperature:mlx90632: Adding extended calibration option")
Applied to the fixes-togreg branch of iio.git and marked for stable.
Thanks,
Jonathan
> ---
> drivers/iio/temperature/mlx90632.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
> index 503fe54a0bb9..608ccb1d8bc8 100644
> --- a/drivers/iio/temperature/mlx90632.c
> +++ b/drivers/iio/temperature/mlx90632.c
> @@ -248,6 +248,12 @@ static int mlx90632_set_meas_type(struct regmap *regmap, u8 type)
> if (ret < 0)
> return ret;
>
> + /*
> + * Give the mlx90632 some time to reset properly before sending a new I2C command
> + * if this is not done, the following I2C command(s) will not be accepted.
> + */
> + usleep_range(150, 200);
> +
> ret = regmap_write_bits(regmap, MLX90632_REG_CONTROL,
> (MLX90632_CFG_MTYP_MASK | MLX90632_CFG_PWR_MASK),
> (MLX90632_MTYP_STATUS(type) | MLX90632_PWR_STATUS_HALT));
