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Re: Docking stations and ACPI?

On Wed, 18 Jun 2008 20:13:35 -0700
James Chacon <> wrote:

> So I noticed when booting current on my laptop everything maps
> cleanly under ACPI now (including the previously broken cardbus back
> in the pre 4.0 days).
> However there's no driver for the dock. Running acpidump on this  
> laptop shows it described correctly and it provides EJD tags for any  
> devices it's passing through to the doc (com, lpt and usb in my case).
> What I was wondering is if there's any current plans for drivers for  
> docks? It's been a significant amount of time since I last looked at  
> things so wanted to know if anyone was already looking at this.
>  From what I can tell the sequence for dealing with docks would be:
> Issue some form of "please allow eject" from a dock call.
> For all devices containing an EJD tag for that dock, attempt a
> detach on them. For things which are in active use (USB drives, etc)
> fail of course until they're ready.
> OS side does a _DCK(0) call (blocks until dock is ready)
> OS issues an asych _EJ0 call
> ACPI completes this once the actual undock has happened
> Rescan devices that had EJD tags associated with this dock and  
> reattach any that are still around.
> i.e. on my laptop the com/lpt ports are pass-through out to the
> dock. So after eject they're still around and active and should be  
> reattached, but not all the USB ports are there (the dock has a
> couple more exposed).
> I'm assuming the user level side of this could be augmented support
> in eject(1) and possibly a dock device to call against.
> Does this sound sane as a start?
Presumably, some of that could be done at user level via drvctl.
Reattaching is trickier, though I think drvctl can do that, too.

                --Steve Bellovin,

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