Am Mittwoch, den 28.06.2017, 14:01 +0200 schrieb Greg KH:
> On Wed, Jun 28, 2017 at 11:19:09AM +0200, Oliver Neukum wrote:
> >
> > Am Mittwoch, den 28.06.2017, 08:07 +1000 schrieb Stuart Longland:
> >
> > Hi,
> >
> > >
> > > >
> > > > >
> > > > > and to select 4-wire ("full duplex") RS-485, one does:
> > > > > # echo rs485fd > /sys/class/tty/ttyUSB0/standard
> > > > This looks like something that people will put into udev.
> > > > So the switch will be done via udev, but the user not necessarily
> > > > started via udev. Looks like a race to me.
> > >
> > > It is a race, but unless a daemon is watching for the very moment that a
> > > particular serial interface appears, it's one that init scripts are very
> > > likely to win.
> >
> > That is precisely what a demon might do.
> >
> > >
> > > Short of having a flag that blocks reads/writes until a given sysfs file
> > > is written to say "I'm ready, go ahead"… there aren't that many options
> > > I can think of.
> >
> > 1) module option
>
> No, just no, sorry.
>
Hi,
I am sorry, but this is just ideological an answer. This is rather
specialized hardware, so it will need a system specifically configured
for this task. No distro will configure this on the fly.
Regards
Oliver
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