Recommendations for a serial port card you can actually BUY?

Karl Denninger karl at
Mon Oct 9 00:10:07 UTC 2006

On Sun, Oct 08, 2006 at 04:14:44PM +0200, Matthias Andree wrote:
> Karl Denninger <karl at> writes:
> > Uh, if you unplug a working serial device's USB cable, you've got bigger
> > problems :)
> So you think? USB is hotplug, and it doesn't have to be a port in use
> that you're unplugging.

I realize that but my point is that if you unplug a serial port that has a
process connected to it you're going to yank its file descriptor out from
under it, and it will not be pleased about that!

> > If you plug and unplug ONLY ONE, it should ID in the same place, since
> > there's a "hole".  If you plug / unplug more than one, I can live with the
> > penalty being a required reboot.  After all, these are NOT supposed to be
> > tampered with while the machine is running!
> OK, that makes things easier.
> Perhaps un-/reloading the kernel driver modules (if compiled as module)
> is sufficient anyways -- the module will probably reprobe everything upon
> reload; OTOH you can check usbd and devd and things if you can pin
> devices to certain ordering.

I'm likely going to have a shell script that runs at boot and creates a
"local device" directory with symlinks to the ucom ports involved, based on
their physical location.  This way Device #1 that is connected to USB Serial
Adapter #1 can always open /ldev/usb-serial1 and GET the first USB serial
device (plugged into the first physical USB port), no matter in what order
they identify.

Karl Denninger (karl at Internet Consultant & Kids Rights Activist	My home on the net - links to everything I do!		Your UNCENSORED place to talk about DIVING!	Musings Of A Sentient Mind

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