Re: hwmon (nct6775): Please fix Invalid temperature source error for NCT6798D

[Stefan Dietrich <roots@gmx.de>]

On Mon, 2020-07-13 at 22:18 -0700, Guenter Roeck wrote:
> On 7/13/20 10:40 AM, Stefan Dietrich wrote:
> > On Sun, 2020-07-12 at 15:46 -0700, Guenter Roeck wrote:
> > > On Sun, Jul 12, 2020 at 09:51:42AM +0200, Stefan Dietrich wrote:
> > > > On Sun, 2020-07-05 at 07:21 -0700, Guenter Roeck wrote:
> > > [ ... ]
> > > > Would you mind giving me a pointer on how this would be done? I
> > > > assume
> > > > for those familiar with the driver it will be less than a
> > > > handful
> > > > of
> > > > lines of code?!
> > > > I will certainly report back as soon as I have obtained any
> > > > results.
> > >
> > > Something like the diffs below should do. Caution - this is cut-
> > > and-
> > > paste,
> > > so you'll have to make the changes manually.
> > >
> > > Guenter
> > >
> > > ---
> > > diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
> > > index 7efa6bfef060..ec427ce503f0 100644
> > > --- a/drivers/hwmon/nct6775.c
> > > +++ b/drivers/hwmon/nct6775.c
> > > @@ -786,9 +786,9 @@ static const char *const nct6798_temp_label[]
> > > = {
> > >         "Agent1 Dimm1",
> > >         "BYTE_TEMP0",
> > >         "BYTE_TEMP1",
> > > -       "",
> > > -       "",
> > > -       "",
> > > +       "Unknown28",
> > > +       "Unknown29",
> > > +       "Unknown30",
> > >         "Virtual_TEMP"
> > >  };
> >
> > Dankeschoen - I just tried that, but I'm still getting
> >
> > [  324.901595] nct6775 nct6775.656: Invalid temperature source 28
> > at
> > index 0, source register 0x100, temp register 0x73
> > [  324.901637] nct6775 nct6775.656: Invalid temperature source 28
> > at
> > index 1, source register 0x200, temp register 0x75
> > [  324.901679] nct6775 nct6775.656: Invalid temperature source 28
> > at
> > index 2, source register 0x300, temp register 0x77
> > [  324.901722] nct6775 nct6775.656: Invalid temperature source 28
> > at
> > index 3, source register 0x800, temp register 0x79
> > [  324.901765] nct6775 nct6775.656: Invalid temperature source 28
> > at
> > index 4, source register 0x900, temp register 0x7b
> > [  324.901807] nct6775 nct6775.656: Invalid temperature source 28
> > at
> > index 5, source register 0xa00, temp register 0x7d
> >
> > I double checked that it really is the modified driver that is
> > loaded.
> > Now does that mean the diffs did not do the trick, or that there's
> > really nothing to see here?
> >
>
> I forgot: Also change NCT6798_TEMP_MASK to 0xffff0ffe.

The error messages are gone and sensors now shows a value for source
Unknown28. However, I did not figure out which component's temperature
it corresponds to. It is definitely not one of the three 2-pin
temperature sensor headers on the mainboard, as I swapped external temp
sensors on these without impact on the reported value. The shown value
is in the range of the CPU core temperatures (that is, somewhere
between roughly 30 and 80°C) and varies with 0.5°C resolution.

However - thanks a lot for your assistance. If I may be of help in
further debugging for that particular NCT chip / mainboard, please let
me know!

Thanks,
Stefan