From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tobias Arp" Subject: Re: ST16C654 stoppes transmitting after a while Date: Tue, 17 Jul 2012 13:36:03 +0200 Message-ID: <20120717113603.9830@gmx.net> References: <20120717074355.80180@gmx.net> <20120717105229.17b578a5@pyramind.ukuu.org.uk> <20120717100521.219440@gmx.net> <20120717122140.075aa7ae@pyramind.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: Received: from mailout-de.gmx.net ([213.165.64.22]:34335 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751847Ab2GQLgH (ORCPT ); Tue, 17 Jul 2012 07:36:07 -0400 In-Reply-To: <20120717122140.075aa7ae@pyramind.ukuu.org.uk> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Alan Cox Cc: linux-serial@vger.kernel.org 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 > An: "Tobias Arp" > 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" 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