Re: wrong ACPI estimate (fwd)

[Alexey Starikovskiy <astarikovskiy@suse.de>]

Len Brown wrote:
> Alexey, Henrique,
> Is this related to the power supply sysfs wrong-units bug?
Yes.

Regards,
Alex.
> 
> thanks,
> Len Brown, Intel Open Source Technology Center
> 
> ---------- Forwarded message ----------
> Date: Thu, 15 Jan 2009 10:14:41 -0800
> From: "Kok, Auke" <auke-jan.h.kok@intel.com>
> To: Winfried Tilanus <winfried@tilanus.com>
> Cc: "power@bughost.org" <power@bughost.org>
> Subject: Re: wrong ACPI estimate
> 
> Winfried Tilanus wrote:
>> Hi,
>>
>> I am running Debian Lenny on a thinkpad x61s, with tp_smapi modules. I
>> incorrectly thought the following problem was fixed:
>>
>> $ sudo powertop -d | grep "Power usage"
>> Power usage (ACPI estimate): 200.4W (0.3 hours)
>>
>> This problem is discussed in Debian bug 497929
>> (http://bugs.debian.org/497929)
>> The problem is fixed by reverting the a code change mentioned there:
>>
>> @@ -644,7 +651,7 @@ void print_battery_sysfs(void)
>>                         continue;
>>                 memset(line, 0, 1024);
>>                 if (fgets(line, 1024, file) != NULL) {
>> -                       watts_drawn = strtoull(line, NULL, 10) / 1000000.0;
>> +                       amperes_drawn = strtoull(line, NULL, 10) /
>> 1000000.0;
>>                 }
>>                 fclose(file);
>>
>> Is there a way to fix this?
> 
> I doubt that we can fix this for everyone :/
> 
> unfortunately it seems that the numbers reported back to the kernel are of
> different types on various systems.
> 
> I will revert this change in the next release, just because the initial change
> that did this did not take this into account, and I'd rather be back at the
> initial (broken) stage than another (broken) stage.
> 
> We'll have to figure out we somehow can distinguish between the two units when we
> read the data, which will likely be more complex, or involve fixing various ACPI
> drivers to unify their number reporting.
> 
> Auke
> 
> _______________________________________________
> Power mailing list
> Power@bughost.org
> http://www.bughost.org/mailman/listinfo/power