Re: [BUG] [hwmon] linux 2.6.31-rc6 regression

From: Matthew Garrett
Date: Sat Aug 15 2009 - 21:03:16 EST


On Sat, Aug 15, 2009 at 01:29:48PM +0300, Zeev Tarantov wrote:

> [ 3.276720] w83627ehf: Found W83627DHG chip at 0x290
> [ 3.276894] ACPI: I/O resource w83627ehf [0x295-0x296] conflicts
> with ACPI region HWRE [0x290-0x299]
> [ 3.277171] ACPI: Device needs an ACPI driver

The hwmon driver is attempting to allocate a region that's also used by
your ACPI firmware. There's no way to synchronise access between the
kernel and the firmware, so allowing both is potentially racy - we've
seen numerous cases where the combination results in the system
incorrectly generating critical temperatuer shutdowns, for instance,
when some other indexed access gets interpreted as the temperature or
when the hwmon chip's state machine is confused. The failure of hwmon to
bind is a feature here, not a bug. You can override it with
acpi_enforce_resources=no on the kernel command line.

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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