Re: [PATCH 3/5] power: supply: cpcap-battery: invalidate empty->counter_uah and charge_full when they are grossly wrong

[Sebastian Reichel <sebastian.reichel@collabora.com>]

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Hi,

On Sun, Jan 17, 2021 at 10:46:38PM +0100, Carl Philipp Klemm wrote:
> This invalidates empty->counter_uah and charge_full when charge_now indicates
> that they are grossly wrong and adds some tolerance to
> POWER_SUPPLY_PROP_CHARGE_FULL to allow for inaccuracies in the charge counter
> and manufacturing tolerances in the battery.
> 
> Signed-off-by: Carl Philipp Klemm <philipp@uvos.xyz>
> ---
>  drivers/power/supply/cpcap-battery.c | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
> index 86ed41d9627f..8ae0c9c7ebcb 100644
> --- a/drivers/power/supply/cpcap-battery.c
> +++ b/drivers/power/supply/cpcap-battery.c
> @@ -667,10 +667,22 @@ static int cpcap_battery_get_property(struct power_supply *psy,
>  		if (!empty->voltage)
>  			return -ENODATA;
>  		val->intval = empty->counter_uah - latest->counter_uah;
> -		if (val->intval < 0)
> +		if (val->intval < 0) {
> +			if (ddata->charge_full && abs(val->intval) > ddata->charge_full/5) {

Please add a comment what this check is doing. It's hard to grasp
without context of the commit when reading the driver at a later
point.

/* Assume invalid config if CHARGE_NOW is -20% */

> +				empty->voltage = 0;
> +				ddata->charge_full = 0;
> +				return -ENODATA;
> +			}
>  			val->intval = 0;
> -		else if (ddata->charge_full && ddata->charge_full < val->intval)
> +		}
> +		else if (ddata->charge_full && ddata->charge_full < val->intval) {

put closing curly bracket into the same line as the else. Also
please add sth. like

/* Assume invalid config if CHARGE_NOW exceeds CHARGE_FULL by 20% */

> +			if (val->intval > (6*ddata->charge_full)/5) {
> +				empty->voltage = 0;
> +				ddata->charge_full = 0;
> +				return -ENODATA;
> +			}
>  			val->intval = ddata->charge_full;
> +		}
>  		break;
>  	case POWER_SUPPLY_PROP_CHARGE_FULL:
>  		if (!ddata->charge_full)
> @@ -747,7 +759,7 @@ static int cpcap_battery_set_property(struct power_supply *psy,
>  	case POWER_SUPPLY_PROP_CHARGE_FULL:
>  		if (val->intval < 0)
>  			return -EINVAL;
> -		if (val->intval > ddata->config.info.charge_full_design)
> +		if (val->intval > (6*ddata->config.info.charge_full_design)/5)
>  			return -EINVAL;
>  
>  		ddata->charge_full = val->intval;

-- Sebastian

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