Subject: Re: ACPI userland issues
To: Chapman Flack <nblists@anastigmatix.net>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: current-users
Date: 06/22/2006 09:10:38
On Thu, 22 Jun 2006 09:04:31 -0400, Chapman Flack
<nblists@anastigmatix.net> wrote:

> Steven M. Bellovin wrote:
> > 	arguably I should have told it that I was doing this.  Of
> > 	course, there's currently no way to tell acpi about switches,
> > 	whether it's inserting or removing an Ultrabay DVD drive
> 
> ACPI /should/ be able to tell /you/. The switchable devices should all
> be marked as such in the DSDT, with AML methods given for testing their
> presence and handling change notifications from the hardware (if we're
> not asleep at the time). If we are asleep, we're supposed to check such
> devices on wake.
> 
> Now, whether we're yet /doing/ any of that is another question, but
> once implementation is complete, it should not be necessary to tell
> ACPI that you've switched something.
> 
> Some UI will still be needed to tell ACPI you intend to switch something,
> though, in case the something has AML methods that need to be run first
> to put it in a depowered, safe-to-remove state.
> 
Yes, this is exactly what I'm asking for; thanks for clarifying it -- I
spoke imprecisely.

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb