[Debian-eeepc-devel] 701 battery capacity has wrong dimension?

[Patrick Strasser]

Axel Beckert wrote am 2008-11-03 13:54:

> So the question now is: Is it a bug in the driver (does not recognize
> the percentage values) 

I don't think there is an easy way to recognize the wrong dimension. Not 
directly shown by thi proc interface is the Power Unit field, which can 
have two values, mAh and mWh. These are implicit added to the values of 
the rest of the fields. Battery Technology is the field to decide if the 
battery is rechargeable or not. So the only and not very robust way to 
find out if an implementation is broken in the EeePC-way is to look at 
the capacity values and guess if they resemble something like 
percentages instead of mAh or mWh. So if Design Capacity is much larger 
then Last Full Capacity, the battery is either almost dead or reporting 
percentages.

> or does do the correct thing (rechargable
> battery, so it must be mAh) although it's not the right thing, because
> ASUS did not adhere to the ACPI standard.

> I would say the last thing, but this could be fixed in the kernel
> though. Wouldn't be a new thing to fix broken hardware in the driver.

I'm not experienced in kernel driver hacking. Shouldn't this be reported 
on the kernel ACPI list? What steps would be needed to be taken to get 
this fix in?

> What I meant is that since there is at least one case where
> percentages are allowed (non-rechargable batteries), all applications
> should be able to cope with batteries reporting in percentage in
> general.

True. Following the formula should do this. I do not know if any program 
checks for the battery technology and moreover I do not know if there 
are any non-rechargeable battery driven ACPI devices in the wild. 
Nevertheless implementations should do the right thing, just in case.

Patrick
-- 
Engineers motto: cheap, good, fast: choose any two
Patrick Strasser <patrick dot strasser at student dot tugraz dot at>
Student of Telematik, Techn. University Graz, Austria