Re: [lm-sensors] Could the k8temp driver be interfering with ACPI?

Luca Tettamanti
2007-02-20T15:33:57Z

On 2/20/07, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> On Sun, Feb 18, 2007 at 06:38:05PM +0100, Jean Delvare wrote:
>
> > ACPI is broken here, not k8temp, so let's fix ACPI instead. ACPI
> > doesn't conflict with only k8temp, but with virtually all hardware
> > monitoring drivers, all I2C/SMBus drivers, and probably other types of
> > drivers too. We just can't restrict or blacklist all these drivers
> > because ACPI misbehaves.
>
> No, the simple fact of the matter is that if you're running on an ACPI
> platform you need to change some of your assumptions. ACPI owns the
> hardware. The OS doesn't. To an extent this has always been true on
> laptops and servers /anyway/ - the BIOS is free to have a wide variety
> of SMM insanity that invalidates basic assumptions like "If I hold this
> lock, nothing can interrupt me between this write and this read". That's
> simply not true.
>
> So this isn't about fixing ACPI. It's about trying to find a mechanism
> that allows ACPI and raw hardware drivers to coexist, which is made
> somewhat harder by it not being a situation that the platform designers
> have considered in the slightest.

Motherboard vendors usually provide tools for $(TheOtherOS) that can
read from all thermal / fan / voltage / whatever sensors, so I guess
it's possible to make the ACPI driver and the "raw" one play nice with
each other[1].

Luca
[1] Unless their solution is "poke at the hardware and hope that ACPI
doesn't blow up", that is.