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SubjectRe: [PATCH 5/5] power: supply: bq27xxx: Correct supply status with current draw
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Hi,

Le dimanche 28 mai 2017 à 21:16 +0200, Pavel Machek a écrit :
> Hi!
>
> > The status reported directly by the battery controller is not always
> > reliable and should be corrected based on the current draw information.
> >
> > This implements such a correction with a dedicated function, called
> > when retrieving the supply status.
> >
> > @@ -1182,6 +1196,8 @@ static int bq27xxx_battery_status(struct
> > bq27xxx_device_info *di,
> > else
> > status = POWER_SUPPLY_STATUS_DISCHARGING;
> > } else {
> > + curr = (int)((s16)curr) * 1000;
>
> Umm.
>
> > @@ -1190,6 +1206,18 @@ static int bq27xxx_battery_status(struct
> > bq27xxx_device_info *di,
> > status = POWER_SUPPLY_STATUS_CHARGING;
> > }
> >
> > +
> > + if (curr == 0 && status != POWER_SUPPLY_STATUS_NOT_CHARGING)
> > + status = POWER_SUPPLY_STATUS_FULL;
> > +
> > + if (status == POWER_SUPPLY_STATUS_FULL) {
> > + /* Drawing or providing current when full */
> > + if (curr > 0)
> > + status = POWER_SUPPLY_STATUS_CHARGING;
> > + else if (curr < 0)
> > + status = POWER_SUPPLY_STATUS_DISCHARGING;
> > + }
>
> Are you sure this works? On N900, we normally see small currents to/from
> "full" battery.

In my case, this works perfectly and I am quite surprised of what you're
describing. Is it the case when the battery has a PSU connected?

I guess I would consider this a hardware issue (leak currents) and we could
definitely set some range (in device-tree) to distinguish between full + leak
currents and bad reporting from the fuel gauge. That would work well in my case
too.

> Should the test be for absolute_value(curr) < something rather than for == 0?
>
> What hw did you test it on?

I tested this on nyan Chromebooks (Acer Chromebook 13 and HP Chromebook 11) as
well as veyron Chromebooks (Chromebook C201PA) that use a bq27xxx fuel gauge.

Cheers!

--
Paul Kocialkowski, developer of free digital technology and hardware support

Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/[unhandled content-type:application/pgp-signature]
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