Re: [PATCH-tip] x86: hwmon/k8temp.c Add support for AMD 10H and 11H

[Jaswinder Singh Rajput <jaswinder@kernel.org>]

On Sat, 2009-05-23 at 18:59 +0200, Rudolf Marek wrote:
> Hi,
> 
> Yes it works for most CPUs, but for unlucky users we might get complains from 
> them - and false alarms.
> 
> I'm talking about:
> 
> http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/41322.pdf
> 
> Errata #319
> 
> So far all CPUs have the issue.

>From manual :

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
319 Inaccurate Temperature Measurement
Description
The internal thermal sensor used for CurTmp (F3xA4[31:21]), hardware thermal control (HTC),
software thermal control (STC) thermal zone, and the sideband temperature sensor interface (SB-TSI)
may report inconsistent values.
Potential Effect on System
HTC, STC thermal zone, and SB-TSI do not provide reliable thermal protection. This does not affect
THERMTRIP or the use of the STC-active state through StcPstateLimit or StcPstateEn
(F3x68[30:28, 5]).
Suggested Workaround
None. Systems should be designed with conventional thermal control and throttling methods or
utilize PROCHOT_L functionality based on temperature measurements from an analog thermal diode
(THERMDA/THERMDC).
Systems should not rely on the HTC features, STC thermal zone features, or use SB-TSI.
Software should not modify HtcTmpLmt (F3x64[22:16]) or enable any of the STC thermal zone
features by setting StcApcTmpLoEn, StcApcTmpHiEn, StcSbcTmpLoEn, or StcSpcTmpHiEn
(F3x68[3:0]).

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

It seems that this problem is for some K10 processors.
And K11 is OK, right ?

I think our patch is safe enough and we will fix the problem for some
K10 processors or in the worst case we will remove support for that
particular cpu.

Ingo: do you mind to applying this patch on -tip and lets see its
feedback and fix the problem.

Thanks
--
JSR