Re: [PATCH] ACPI: battery: add sysfs serial number

[Alexey Starikovskiy <astarikovskiy@suse.de>]

Sjoerd Simons wrote:
> On Wed, Jan 23, 2008 at 02:01:34PM +0300, Alexey Starikovskiy wrote:
>> maximilian attems wrote:
>>> got the following question:
>>> ~/src/hal$ egrep 'voltage_(max|min)_design' -r .
>>> ./hald/linux/device.c:  if (hal_util_get_int_from_file (path, "voltage_max_design", &voltage_design, 10)) {
>>>
>>> any particular reason the kernel is calling it
>>> cat /sys/class/power_supply/BAT0/voltage_min_design 14400000
>>>
>>> shall i send in a patch along the line:
>>> -       case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
>>> +       case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
>>>                 val->intval = battery->design_voltage * 1000;
>>>
>>> or is it hal beeing silly?
>>>
>> On most new batteries design voltage is less than current voltage, thus I've chosen VOLTAGE_MIN_DESIGN.
>> On older batteries, current voltage may become lower than design, so I 
>> think hal should not be very strict about how they relate to each other. 
> 
> I'll patch up hal to use voltage_min_design if there is no voltage_max_design
> available. Which should be fine as we already picked up the same value from
> procfs for this property.
> 
> What it does make me wonder about, is why there is a difference between MIN and
> MAX in the power_supply class. As this doesn't seem to have a strict meaning
> (or at least not for ACPI). So why not just voltage_design instead ?
Don't know, may be they had battery for which both min and max voltages are known and 
crossing each needs to be guarded...

Regards,
Alex.