probe-serial.c does not work on /dev/ttyACM0

[Bill Nottingham]

Sjoerd Simons (sjoerd at luon.net) said: 
> On Thu, Feb 16, 2006 at 09:45:38PM +0100, Kay Sievers wrote:
> > Hi Pierre,
> > did you test the serial prober with anything but plain old serial
> > ports? I seems to fail with serial USB devices, common in mobile
> > phones:
> >    open("/dev/ttyACM0", O_RDONLY|O_NONBLOCK|O_LARGEFILE) = 3
> >    ioctl(3, TIOCGSERIAL, 0xbff5029c) = -1 EINVAL (Invalid argument)
> 
> Is it really needed to probe non plain old serial ports ? I've just got a
> report that the prober confuses WinCE pda's when connected.

What is it probing for? Generally, the old-style PnP probe sequences *can* be
disruptive to serial consoles and other devices that may be attached.

As to the original query, I thought ttyACM wasn't a true 'serial' device
per-se, as opposed to a USB modem class; the pure usb serial devices 
show up as ttyUSBX.

Bill