Re: [PATCH 2/4] x86/amd_nb: add support for newer PCI topologies

Guenter Roeck
2018-11-07T23:21:54Z

On 11/7/18 1:18 AM, Borislav Petkov wrote:
> On Tue, Nov 06, 2018 at 05:20:41PM -0600, Bjorn Helgaas wrote:
>> Or maybe even drivers/acpi/thermal.c, which claims every Thermal Zone
>> (ACPI 6.2, sec 11), would be sufficient. I don't know what the
>> relationship between hwmon and other thermal stuff, e.g.,
>> Documentation/thermal/sysfs-api.txt is. acpi/thermal.c looks tied
>> into the drivers/thermal stuff (it registers "thermal_zone" devices),
>> but not to hwmon.
>
> Err, I still don't think I'm catching your drift but let me stop you
> right there: amd_nb is not there only for hwmon/k10temp. It is a small
> interface glue if you will, which exports the CPU functionality in PCI
> config space to other consumers.
>

Also, thermal and hwmon are orthogonal, just like hwmon and iio. One would
typically have a driver in one subsystem, in some cases bridging to the
other subsystem, but one would not have drivers in both subsystems.
I think Bjorn is suggesting that the k10temp driver should move to the
thermal subsystem, though I don't really understand what that has to do
with finding the correct PCI device(s) to query. Or maybe I misunderstand.

Guenter

> So it is not really a driver - it is used by drivers to talk/query CPU
> settings through it.
>
> With that said, I don't think I understand all that talk about PNP IDs
> and ACPI methods. But maybe I'm missing something...
>
> So what's up?
>