[HEADSUP] ACPI-CA 20070126 import

[Nate Lawson]

Jung-uk Kim wrote:
> On Monday 19 March 2007 10:58 am, Patrick Tracanelli wrote:
>> Is it 3.0(a) revision?
> 
> ACPI-CA should support ACPI 3.0b spec. but we (FreeBSD) do not use 
> much of the features.

One misconception a lot of people have is that acpi is like a piece of
hardware that has a driver.  So they think the driver should support
version 3.0b or whatever.

acpi is more like an API to your BIOS/hardware that many other drivers
use.  We "support" version 3.0b in that if drivers want to use it, that
information is available.  But the actual support in terms of enabling
features still requires a lot more work.

For example, hotplug cpus.  Nothing needs to be done in acpi to support
them.  But FreeBSD needs a driver for hotplug cpus, architecture changes
to help migrate threads off a cpu before shutting it down, etc.

-- 
Nate