[Nut-upsdev] Re: Serial Ports (Was Re: Common Power Management : NUT and HAL (stage 1))

[David Zeuthen]

On Wed, 2006-09-13 at 13:21 +0200, Arnaud Quette wrote:
> 2006/9/12, Charles Lepple <clepple at gmail.com>:
> > On 9/11/06, Matthew Garrett <mjg59 at srcf.ucam.org> wrote:
> > > It's a protocol for identifying pretty much any serial device made after
> > > 1994. The specs are on Microsoft's website somewhere, but I'm never able
> > > to find them when I look...
> >
> > I've had trouble locating them from time to time as well. Here they are:
> >
> > http://www.microsoft.com/whdc/resources/respec/specs/pnpcom.mspx
> >
> > There are a lot of inexpensive UPSes out there where I would be
> > surprised if they actually implemented serial PnP, though.
> 
> one more reference on the subject
> http://lists.alioth.debian.org/pipermail/nut-upsdev/2006-March/000778.html
> 
> @David: I remember seing something about PnP in HAL. Is there any
> *serial* PnP support, which is the thing that interest us?

No, but we can add this. The way I understand is that it just attempts
send a command on the serial port and gets back one or more values. 

What we do with this data we'd have to look at, I think each HAL serial
prober would simply add a new property

 legacy_port.probers.pnp_ids_supported 

as described in step 2. of

 http://lists.freedesktop.org/archives/hal/2006-August/005784.html

and if we find something we autoselect serial port model, driver and
options as good as we can. 

The user interaction would still be the same as described in

 http://lists.freedesktop.org/archives/hal/2006-September/006103.html

except between step 1. and 2. we now have "user can press the
Probe-For-Device button" and if that gives something useful we a) might
not need to bother him with selecting the device; or b) auto selecting
device type (e.g. UPS, modem, mouse etc.) and possibly driver and
options for him.

Does this sound good?

Also: we certainly can't run serial PNP probing automatically, only in
response to a user choice of deciding to probe for serial ports. I say
this because maybe it will crash some old devices or some that don't
support Serial PNP. This is correct, yes?

    David