Re: [PATCH v3] power/supply: ingenic-battery: Don't change scale if there's only one

[Artur Rojek]

On 2019-11-16 14:56, Paul Cercueil wrote:
> The ADC in the JZ4740 can work either in high-precision mode with a 
> 2.5V
> range, or in low-precision mode with a 7.5V range. The code in place in
> this driver will select the proper scale according to the maximum
> voltage of the battery.
>
> The JZ4770 however only has one mode, with a 6.6V range. If only one
> scale is available, there's no need to change it (and nothing to change
> it to), and trying to do so will fail with -EINVAL.
>
> Fixes: fb24ccfbe1e0 ("power: supply: add Ingenic JZ47xx battery 
> driver.")
>
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

Looks good to me!

Acked-by: Artur Rojek <contact@xxxxxxxxxxxxxx>

> ---
>
> Notes:
>     v2: Rebased on v5.4-rc7
>     v3: Move code after check for max scale voltage
>
>  drivers/power/supply/ingenic-battery.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/power/supply/ingenic-battery.c
> b/drivers/power/supply/ingenic-battery.c
> index 35816d4b3012..2748715c4c75 100644
> --- a/drivers/power/supply/ingenic-battery.c
> +++ b/drivers/power/supply/ingenic-battery.c
> @@ -100,10 +100,17 @@ static int ingenic_battery_set_scale(struct
> ingenic_battery *bat)
>  		return -EINVAL;
>  	}
>
> -	return iio_write_channel_attribute(bat->channel,
> -					   scale_raw[best_idx],
> -					   scale_raw[best_idx + 1],
> -					   IIO_CHAN_INFO_SCALE);
> +	/* Only set scale if there is more than one (fractional) entry */
> +	if (scale_len > 2) {
> +		ret = iio_write_channel_attribute(bat->channel,
> +						  scale_raw[best_idx],
> +						  scale_raw[best_idx + 1],
> +						  IIO_CHAN_INFO_SCALE);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
>  }
>
>  static enum power_supply_property ingenic_battery_properties[] = {