Messages in this thread | | | Date | Mon, 09 Dec 2013 23:25:15 +0100 | From | Jan Včelák <> | Subject | Re: [PATCH] ACPI: full battery charge cannot exceed current one |
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>> Some degraded batteries report maximal capacity to be smaller than >> current charge of the battery. This can confuse some user space >> applications (like upower). > > Can't we just fix upower?
It looks like upower already resolved that:
http://cgit.freedesktop.org/upower/tree/src/linux/up-device-supply.c#n652
If the purpose of sysfs is to provide raw values retrieved from battery, then I agree that this should not be handled in kernel. Otherwise I would expect semantically correct data there.
>> + /* Some degraded batteries report lower full charge than current one. */ >> + if (battery->capacity_now > battery->full_charge_capacity) >> + battery->full_charge_capacity = battery->capacity_now; >> + > > Does upower read *_full on every read of the value? How do we guarantee > that it won't read energy_now without updating energy_full and still > come up with an incorrect calculation?
That's a good point. I'm not sure about other applications, but upower always refreshes all values. Function up_device_supply_refresh_battery seems to be the only place where 'charge_now' is being read:
http://cgit.freedesktop.org/upower/tree/src/linux/up-device-supply.c#n485
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