amdtemp(4) issue

[Jung-uk Kim]

On Wednesday 05 May 2010 01:51 pm, Jung-uk Kim wrote:
> On Wednesday 05 May 2010 02:43 am, Norikatsu Shigemura wrote:
> > Hi jkim.
> >
> > 	I can't get CPU temperature via amdtemp(4).  So I researched,
> > but I can't fix this issue, maybe initialization problem.  Please
> > help me!
> >
> > 	1st issue in amdtemp_gettemp function:
> > 		now:		offset += (diode_offset - 11) * 10;	is BAD
> > 		should fix:	offset += (11 - diode_offset) * 10;	is OK
> > 	According to AMD's BIOS and Kernel Developer's Guid (BKDG) For
> > 	AMD Family 10th Processors, Rev 3.48 - April 22, 2010 [*],
> > 	P327 - F3xE4 Thermtrip Status Register:
> >
> > 01h to 3Fh: correction = +11C - DiodeOffset, or {01h to 3Fh} =
> > {+10C to -52C}.
> >
> > 	In fact, in my environment, DiodeOffset = 0x18 so 11-0x18=-13C.
> >
> > 11 - 0x01 = +10C
> > 11 - 0x18 = -13C
> > 11 - 0x3f = -52C
> >
> > [*] http://support.amd.com/us/Processor_TechDocs/31116.pdf
>
> AMD keeps flipping the sign from core to core. :-( Please see
> AMDTEMP_FLAG_DO_SIGN for Family 0Fh, for example.  In fact, Linux
> driver (k10temp) does not care about the DiodeOffset at all.
> Instead, they just say "input" temperature.
>
> > 	2nd issue, result of AMDTEMP_REPTMP_CTRL in amdtemp_gettemp
> > function: I got following result:
> >
> > May  5 15:06:53 nadesico kernel: amdtemp0:
> > AMDTEMP_REPTMP_CTRL(temp) = 0xc1880
> >
> > 	So result (CurTmp: current temperature: 31:21) = 0C. (logic is
> > OK)
> >
> > 	I got following thermal related registers in amdtemp_gettemp
> > function: May  5 15:06:53 nadesico kernel: amdtemp0: F3x64
> > Hardware Thermal Control(HTC) Register = 0x3a4c0005 May  5
> > 15:06:53 nadesico kernel: amdtemp0: F3x68 Software Thermal
> > Control(STC) Register = 0x10000000 May  5 15:06:53 nadesico
> > kernel: amdtemp0: F3xA4 Reported Temperature Control Register  =
> > 0x000c1880 May  5 15:06:53 nadesico kernel: amdtemp0: F3xE4
> > Thermtrip Status Register = 0x1cc01830 May  5 15:06:53 nadesico
> > kernel: amdtemp0: F3xE8 Northbridge Capabilities Register      =
> > 0x0207df19
> >
> > 	But I don't have any idea to fix register's paraemters.  Do you
> > 	have any idea?
>
> Sorry, I don't.  You may find Linux k10temp driver
> (drivers/hwmon/k10temp.c) useful, though.

Actually more useful reference code for us would be kate(4)/km(4) from 
OpenBSD and amdtemp(4) from NetBSD:

http://www.openbsd.org/cgi-bin/cvsweb/src/sys/dev/pci/kate.c
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/dev/pci/km.c
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/x86/pci/amdtemp.c

Jung-uk Kim