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

[Stefan Dietrich <roots@gmx.de>]

On Sun, 2020-07-05 at 07:21 -0700, Guenter Roeck wrote:
> On 7/5/20 6:19 AM, Stefan Dietrich wrote:
> > On Fri, 2020-07-03 at 10:10 -0700, Guenter Roeck wrote:
> > > On 7/3/20 9:03 AM, Stefan Dietrich wrote:
> > > > Hi all,
> > > >
> > > > with my Asus Formula XII Z490 and 5.7.0-7.1-liquorix-amd64 I'm
> > > > getting
> > > > the following error messages during boot:
> > > >
> > > > nct6775: Found NCT6798D or compatible chip at 0x2e:0x290
> > > > nct6775 nct6775.656: Invalid temperature source 28 at index 0,
> > > > source
> > > > register 0x100, temp register 0x73
> > > > nct6775 nct6775.656: Invalid temperature source 28 at index 1,
> > > > source
> > > > register 0x200, temp register 0x75
> > > > nct6775 nct6775.656: Invalid temperature source 28 at index 2,
> > > > source
> > > > register 0x300, temp register 0x77
> > > > nct6775 nct6775.656: Invalid temperature source 28 at index 3,
> > > > source
> > > > register 0x800, temp register 0x79
> > > > nct6775 nct6775.656: Invalid temperature source 28 at index 4,
> > > > source
> > > > register 0x900, temp register 0x7b
> > > > nct6775 nct6775.656: Invalid temperature source 28 at index 5,
> > > > source
> > > > register 0xa00, temp register 0x7d
> > > >
> > >
> > > There is nothing much if anything we can do about that. The
> > > NCT6798D
> > > datasheet reports temperature source 28 as reserved.
> >
> > Thanks for the quick reply. Would you briefly outline why this
> > makes it
> > inaccessible for the NCT6776 driver? Is there a pool of registers
> > that
> > I might probe for values that could be related to the desired
> > temperature values, even if they need to be scaled?
> >
>
> Reserved means invalid for use. We don't know what happens if we
> would
> let the driver use those values. That has nothing to do with scaling.
>
> If you like, feel free to modify the driver to accept temperature
> source
> 28 for NCT6798D and report the results. That should give us an idea
> if
> the datasheet is at fault or the board BIOS.

Ok, thanks. Unfortunately, a look at the code tells me that this is
beyond my current skills, but I might start toying around with it some
day ;-)


Stefan

> Guenter