Phenom II 975 BE shows 0 celsius

[Jung-uk Kim]

On Sunday 31 July 2011 08:28 pm, Mario Lobo wrote:
> Hi to all
>
> In my desktop machine, I had an AM2+ ASROCK mobo with Phenom II 955
> BE that showed each core temperature perfectly under FBSD 8-STABLE,
> via dev.cpu.x.temp. amdtemp.ko loaded.
>
> Unfortunately this Mobo died and only found AM3 boards for which my
> phenom 955 doesn't fit. So I got an ASUS M4A88T-V EVO with a Phenom
> II 975 BE.
>
> Funny thing. An AM3 phenom II fits on an AM2 board but an AM3 board
> doesn't accept an AM2/AM2+ phenom II :(.
>
> Anyway, now, under the very same system, it shows 0 degrees on
> dev.cpu.x.temp for all cores.
>
> I've been looking through k8temp and amdtemp src code. I am
> definitely not
>
> sure of this but I believe something might have happened to those:
> >From k8temp.h
>
> K10_THERM_REG      0xa4
> K10_THERMTRIP_REG  0xe4
> K10_CURTMP(val)    (((val) >> 21) & 0xfff)
> K10_THERMTRIP(val) ((val >> 1) & 1)
>
> >From amdtemp.c
>
> /*
>  * Register control (K8 family)
>  */
> #define	AMDTEMP_REG0F		0xe4
> #define	AMDTEMP_REG_SELSENSOR	0x40
> #define	AMDTEMP_REG_SELCORE	0x04
>
> /*
>  * Register control (K10 & K11) family
>  */
> #define	AMDTEMP_REG		0xa4
>
>
> Output of k8temp -dn:
>
> CPUID: Vendor: AuthenticAMD, 0x100f43: Model=04 Family=f+1
> Stepping=3 Advanced Power Management=0x1f9
>    Temperature sensor: Yes
>  Frequency ID control: No
>    Voltage ID control: No
>     THERMTRIP support: Yes
>    HW Thermal control: Yes
>    SW Thermal control: Yes
>    100MHz multipliers: Yes
>    HW P-State control: Yes
>         TSC Invariant: Yes
> Temp=c0fef
> ThermTrip=1fc00c30
> 0
>
> I keep a small win7 partition to test little things like this and
> see if the same thing happens there, and it doesn't, so I concluded
> that the sensors are there and are working.
>
> One thing is worth noting though. I have used a free gadget that
> shows activity/temp for each core. It worked fine with the previous
> MB/CPU.That ALSO stopped working with this new MB. Like FBSD, it
> shows 0 degrees for any core too, although it correctly displays
> each core load.
>
> The only windows tool that correctly shows the temperature are the
> ASUS tools that came with the mobo.

FYI, FreeBSD has aibs(4) (or acpi_aiboost(4) depending on your FreeBSD 
version) and it does essentially the same thing.

Jung-uk Kim

> Other than that, everything is working fine! The only thing I had
> to fix was the fstab ada location.
>
> I know this is not a big thing but I got accustomed to keeping an
> eye on those temperatures.
>
> I have googled for a few days now searching for Thermal register
> address or offsets for the Phenom II 975 BE, or anything related to
> this problem and found nothing. Every search on AMD site was
> fruitless. I could not find a single bit of tech info on this
> processor there, or any other tech info for that matter.
>
>
> Would any one have any pointers/clues/suggestions on this?
>
> Thanks,