Date: Sun, 24 Feb 2013 22:13:56 -0800 From: Kevin Oberman <rkoberman@gmail.com> To: Dmitry Sarkisov <ait.mlist@gmail.com> Cc: freebsd-acpi@freebsd.org Subject: Re: acpi_termal sysctl interface strange temperature value Message-ID: <CAN6yY1uPiBh6Dv-wsLq1DMcXL%2BD%2Bq_=7s%2B8JbsLk15sN-ZQ-aw@mail.gmail.com> In-Reply-To: <20130225014000.GA6413@aperturescience.org> References: <20130225014000.GA6413@aperturescience.org>
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On Sun, Feb 24, 2013 at 5:40 PM, Dmitry Sarkisov <ait.mlist@gmail.com>wrote:
> Hello,
>
> I'm trying to poll cpu temperature with the following code:
>
>
> #define TEMP_MIB "hw.acpi.thermal.tz0.temperature"
>
> size_t len;
> int t;
>
> len = sizeof(t);
> bzero(temp, len);
>
> if(sysctlbyname(TEMP_MIB, &t, &len, NULL, 0) == -1 ){
> perror("sysctl");
> return -1;
> }else{
> printf("%d\n", t);
> }
>
> Values I'm geting are like this:
> 3732
>
> while actual is:
>
> sysctl -n hw.acpi.thermal.tz0.temperature
> 55.0C
>
ACPI does not report temperature in degrees Celsius, but in tenths of a
degree Kelvin. So both agree.
When ACPI was first introduced into head (v5?), the sysctl reported the
raw number, but the code was later modified to provide a more human
friendly value. Directly probing ACPI for temperature still returns the raw
value.
--
R. Kevin Oberman, Network Engineer
E-mail: rkoberman@gmail.com
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