Re: ST16C654 stoppes transmitting after a while

["Tobias Arp" <tobiasarp@gmx.de>]

This is a single core arm processor (Cirrus EP9315), could this race condition happen in this case? 

But i have CONFIG PRREMPT set. Shall i take a stab on it by switching it to off?

Tobias
-------- Original-Nachricht --------
> Datum: Tue, 17 Jul 2012 12:21:40 +0100
> Von: Alan Cox <alan@lxorguk.ukuu.org.uk>
> An: "Tobias Arp" <tobiasarp@gmx.de>
> CC: linux-serial@vger.kernel.org
> Betreff: Re: ST16C654 stoppes transmitting after a while

> On Tue, 17 Jul 2012 12:05:21 +0200
> "Tobias Arp" <tobiasarp@gmx.de> wrote:
> 
> > I run kernel 3.2. Upgrading to a newer kernel would be not se easy at
> the moment.
> 
> 3.2 is certainly new enough that it should have all the major fixes in.
> 
> > I am not sure how to check if this change is really lost.
> 
> With a debugger dump the state of the port structures one the hung port
> once it has hung. Something like Red Hat's systemtap might also be very
> helpful in doing this kind of monitoring.
> 
> My first guess would be that you hit a race between the port stopping on
> one processor and the flow control event on another. We have one known
> case there still being debugged but I thought it could only be hit if you
> were using ttys in low latency mode.
> 
> Alan