[Debian-eeepc-devel] debian on eeepc 1201N : Pb with smbus nforce2

[Alan Jenkins]

On 1/6/10, giggzounet <giggzounet at gmail.com> wrote:
> Hi,
>
> With the kernel of lenny bakcport 2.6.30 the module i2c_nforce2 loads
> without problem : in dmesg I see :
>
> [    6.569759] i2c-adapter i2c-0: nForce2 SMBus adapter at 0x4d00
> [    6.569905] i2c-adapter i2c-1: nForce2 SMBus adapter at 0x4e00
>
>
> With the 2.6.32.2 I see :
> [    3.842775] i2c i2c-0: nForce2 SMBus adapter at 0x4d00
> [    3.842861] ACPI: I/O resource nForce2_smbus [0x4e00-0x4e3f]
> conflicts with ACPI region SM00 [0x4e00-0x4e3f]
> [    3.842949] ACPI: If an ACPI driver is available for this device, you
> should use it instead of the native driver
> [    3.843036] nForce2_smbus 0000:00:03.2: Error probing SMB2.
>
>
> What can I do in order to solve this problem ?

It's only a problem if you have hardware monitoring sensors you want
to use on that bus, for whatever reason.

If you know the kernel is being over-cautious because you've inspected
the DSDT etc. and found that the ACPI BIOS doesn't actually use the
SM00 region, then you want "acpi_enforce_resources=lax".  (

If you want to see an example of a ACPI hwmon driver, look at the Asus ATK0110.

The third possibility is that the ACPI BIOS uses the sensors for
internal purposes but exposes no interface.  Or more realistically, it
exposes it as an ACPI thermal zone, but omits information like
voltages that you're interested in.

The kernel has to respect these ACPI resource reservations.
Conflicts between the BIOS and kernel driving the same hardware can
cause mysterious slowdowns and worse (and have done so on other EeePC
models).

Alan