minicom bug and linux kernel 2.6.25.4

[R.L. Horn]

On Tue, 10 Jun 2008, Adam Lackorzynski wrote:

> Thanks for your effort. I found my problem... I just used the wrong 
> cable (uuups...). So when I try everything works now, without any 
> modifications in minicom and on 2.6.25. So I can suspect something very 
> special. On the other hand the standard PC stuff should all use the same 
> serial driver, weird... So I suspect there's nothing strange in your 
> dmesg about ttyS? (non-16550A type e.g.)

Nope.

I found a thread in the linux-kernel mailing list that seems to address 
this, but which died without resolution.  Personally, I believe all the 
speculation was way off.

Exactly what I'm seeing is this:

   Opening a serial device brings up DTR and RTS.

   Setting the baud rate to B0 clears DTR and RTS (as per SUS).

   Resetting the baud rate doesn't bring the control lines back up,
   whereas it did under linux-2.6.24.*.  It looks like minicom may be
   unique in its dependence on this behavior.

So, for example, if I run "minicom -o" (thereby skipping the initial 
m_dtrtoggle() call), DTR and RTS are high and everything works as 
expected.

I'm going to try to revive the linux-kernel thread and, hopefully, come up 
with something definitive.