Plans for hal 0.5.x

Andrei Yurkevich urruru at
Tue Dec 14 10:23:59 PST 2004

David Zeuthen wrote:

>>For that reason, HAL could just query the serial interface about 
>>what's on the other side and if that is PDA it could simply tag the 
>>serial interface. Then some callout or daemon that knows how to deal 
>>with different kinds of PDAs (or at leas that kind of PDA connected 
>>there) could create the PDA node below the serial port and set the 
>>necessary properties there.
> You can't really probe a serial port since that may interfere with it's
> operation. I don't think hal should attempt to do that, that's a can of
> worms. E.g. if you really want to support legacy ports in your desktop
> software, you need to take the painful route and do it from your desktop
> sessions - e.g. the "Detect Modem" or "Detect PDA" button and then deal
> with it. No such thing as a free lunch (reminds me; I should go to
> lunch :-)).

Ok, I might have been a little bit wrong here. I didn't mean that HAL
should probe the serial port as such, but look for other hints such as
IrDA discovery messages or information from the bluetooth stack. At
least with IrDA you can know what device is there as soon as the
infrared ports are aligned by means of reading certain files in /proc.
But you are right with legacy serial ports.


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