RE: Ryzen 2700 Temperature offset?

From: Grimm, Jon
Date: Fri Jun 15 2018 - 18:23:16 EST


Hi Rudolf,

Yeah, let me do some checking. I was already aware that our docs were missing this information; need to check if there are actual plans to address or not.

Best Regards,
Jon


> -----Original Message-----
> From: Rudolf Marek <r.marek@xxxxxxxxxxxx>
> Sent: Friday, June 15, 2018 4:57 PM
> To: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>; Grimm, Jon
> <Jon.Grimm@xxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>; Chris Ouellet
> <rabbit.of.war@xxxxxxxxx>; linux-hwmon@xxxxxxxxxxxxxxx; Linux Kernel
> Mailing List <linux-kernel@xxxxxxxxxxxxxxx>
> Subject: Re: Ryzen 2700 Temperature offset?
>
> Hi Jon,
>
> Please can you help?
>
> Thanks
> Rudolf
>
>
> Dne 10.6.2018 v 07:14 Guenter Roeck napsal(a):
> > On Sun, Jun 10, 2018 at 03:03:47AM +0800, Kai-Heng Feng wrote:
> >> at 23:49, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>
> >>> On Thu, Jun 07, 2018 at 11:03:13AM +0800, Kai Heng Feng wrote:
> >>>> Hi Guenter,
> >>>>
> >>>> A user thinks the Ryzen 2700 temperature may not be correct [1].
> >>>> Can you take a look when you have time? Thanks.
> >>>>
> >>>> Also, where can I find all these temperature offsets? I googled but
> >>>> with no result.
> >>> Problem is that the offsets are not documented in public, making it
> >>> difficult to find out. For Ryzen 2700, there is currently no offset
> >>> configured; I was told that there is none. For Ryzen 2700X, the
> >>> offset is 10 degrees C.
> >>
> >> I am still quite interesting where you get this information...
> >>
> > Primarily lots of online research. Windows tools usually support the
> > offsets, so screendumps help in some cases.
> >
> >>>
> >>>> [1] https://bugs.launchpad.net/bugs/1774817
> >>>
> >>> The key here is the commit mentioned in the log (1b59788979acd). It
> >>> does not only adjust the per-CPU offset, but also takes a
> >>> configurable offset of 49 degrees C into account. You'll need to
> >>> apply that patch in your kernel, or the temperature may be off by 49
> degrees C.
> >>
> >> So unless AMD shares these offsets value, we can never know what
> >> correct offsets are?
> >>
> > Unfortunately that is correct.
> >
> > AFAIK the information is available from AMD under NDA. I can not sign
> > such an NDA, and even if I could and would, I could not use the
> > information in an open source driver. Kind of a loose-loose situation.
> > If you (Canonical) have any influence at AMD, it might be useful to
> > let them know that their policy is not very helpful.
> >
> > Guenter
> >
> >
> >> Kai-Heng
> >>
> >>>
> >>> Hope this helps. If not, please let me know. Note that I am
> >>> travelling; responses may be delayed.
> >>>
> >>> Guenter
> >>
> >>
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