On 05/27/2010 07:03 PM, Dmitry Torokhov wrote:

On May 27, 2010, at 5:46 PM, Linus Torvalds
[off-list ref] wrote:

quoted

On Thu, 27 May 2010, Robert Hancock wrote:

quoted

It's highly unlikely that they are incomplete in this respect, as
since I mentioned, Windows would fail to recognize the PS/2 controller
that people would expect to work, which would most likely get
noticed..

Did you miss the part where I actually quoted my own modern Core i5
machine that _does_ have a keyboard controller, and _does_ have a
keyboard
port, and that does _not_ mention them in the PnP tables?

Except that it _does_. But _our_ ACPI implementation drops all inactive
devices so our PNP layer does not see your mouse and keyboard ports.

That's likely true - my machine works similarly, it doesn't list any 
keyboard or mouse controller in PnP and Windows doesn't see them if no 
device is plugged in at boot. The PnP devices for them are still 
defined, but they are marked as disabled (the _STA method in the DSDT 
returns 0). So we could likely detect that case and say "hey, the device 
is there, just turned off, maybe we should try and see if it works 
anyway". Whereas if the device is not there at all, we'd likely be 
better off leaving it alone, by default anyway.

quoted

quoted

I think this is a case where it has to be trusted, because that's what
Windows does.

The thing is, Windows isn't used for things like headless machines. Which
we went over extensively in the thread. There's a _reason_ why Linux
probes the dang thing.