Re: should RTS init in serial core be tied to CRTSCTS

From: Oleksiy Kebkal
Date: Thu Mar 08 2007 - 09:24:09 EST


2007/3/8, Russell King <rmk+lkml@xxxxxxxxxxxxxxxx>:
On Thu, Mar 08, 2007 at 08:44:31AM -0500, Robin Getz wrote:
> On Wed 7 Mar 2007 16:30, Oleksiy Kebkal pondered:
> > 2007/3/7, Robin Getz <rgetz@xxxxxxxxxxxxxxxxxxxx>:
> > > Right - so the question is where to manage the default state? I was
> > > thinking in the resource might be a good idea, but there isn't really a
> > > good place for it. (You could re-use some bits if flags, but I think that
> > > would not be a good idea).
> >
> > /proc/tty/driver/uartN/settings?
> >
>
> That would let you change things are run time, but the problem is at boot
> time. A default setting needs to be set, so when things initialize, and proc
> does not exist yet, it is still set properly...

I disagree. "proc does not exist yet" - the only time that applies is
long before userspace as active.

As I've said already, having a console on the same port as your application
program is just asking for trouble. All bets are off - the kernel _will_
corrupt your data stream in random places.

Don't do it - it will _NEVER_ be reliable.

Never, ever, mix kernel consoles with application serial ports.

Ok. I understand now one of the sources of misunderstanding. I don't
want to mix console and application serial port. It was a question,
Myke Frisinger initially asked. I would switch on/off console
depending on some external control action if possible...

The other problem is how to open serial port with correct settings
_after_ booting. In this case /proc could be applicable, isn't it?

-Oleksiy
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