We do serial differently.

[Kyle Evans]

On Fri, Oct 20, 2017 at 10:03 AM, Ian Lepore <ian at freebsd.org> wrote:

> On Fri, 2017-10-20 at 08:36 -0500, Kyle Evans wrote:
> > This doesn't seem to necessarily be true with ucom(4) bits. I put in a
> bit
> > of effort to try and get devel/libserialport to stop setting DTR when it
> > probes /dev/cuaU* to no avail. As a consequence, connected Arduinos
> > constantly reset when devel/arduino18 is open unless the serial
> > monitor/plotter is also open.
> >
> > I can appreciate that +DTR is a sensible default here, but it would be
> nice
> > if it could be configured with the .init node.
>
> Hmm.  You mention the .init node, does setting -hupcl in the .lock node
> fail to suppress toggling DTR as well?  That, I think, would be a bug.
>
> -- Ian
>

Yeah, that also fails to suppress it. For documentation purposes, this is
the exact device/driver I'm working with:


ugen0.2: <Arduino www.arduino.cc product 0x0043> at usbus0
umodem0 on uhub0
umodem0: <Arduino www.arduino.cc product 0x0043, class 2/0, rev 1.10/0.01,
addr 9> on usbus0
umodem0: data interface 1, has CM over data, has break


When I last poked at it, I think I had decided that this line:
https://svnweb.freebsd.org/base/head/sys/dev/usb/serial/usb_serial.c?view=markup#l735

was the culprit and blatantly ignoring any configuration, but this isn't
exactly an area that I'm familiar with so I assume there might be something
elsewhere that I'm missing.