From mboxrd@z Thu Jan 1 00:00:00 1970 From: Henrik Bork Steffensen Subject: at91_can.c: Data transmission stops Date: Mon, 26 Nov 2012 15:28:32 +0100 Message-ID: <50B37C90.3040904@rosetechnology.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from dmz4.rosetechnology.dk ([95.154.61.7]:46908 "EHLO dmz4.rosetechnology.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752861Ab2KZOhO (ORCPT ); Mon, 26 Nov 2012 09:37:14 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by dmz4.rosetechnology.dk (Postfix) with ESMTP id 3E17EA3028 for ; Mon, 26 Nov 2012 15:28:32 +0100 (CET) Received: from dmz4.rosetechnology.dk ([127.0.0.1]) by localhost (localhost.localdomain [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id IkY3rNYop5TR for ; Mon, 26 Nov 2012 15:28:32 +0100 (CET) Received: from [192.168.36.250] (unknown [95.154.61.6]) by dmz4.rosetechnology.dk (Postfix) with ESMTPA id 18C60A300E for ; Mon, 26 Nov 2012 15:28:32 +0100 (CET) Sender: linux-can-owner@vger.kernel.org List-ID: To: linux-can@vger.kernel.org Hi All, We use the canopen on an at91sam9263, and experience a can problem. Sometimes data transmission simply stops. Data reception continues normally. Reloading the at91_can module seems to be the only action to bring our system back on can. When we experience this problem, the TXF counter in /proc/net/can/stats is frozen. I have followed the thread on a similar issue "pch_can", and I was wondering if this is the same problem, and if the real problem might be in a higher level. In our case the lockup occurs approximately 1 time in 50 days. I tried reducing the number of mailboxes used for TX, from 4 to 1. That seem to increase the frequency of this lockup by a factor 2-5. These numbers are very uncertain due to the randomness and rarity of this bug. Some numbers to give an impression of our system: 125 kbit bus speed can bus load <1% max tx burst 1-6 telegrams, rx is a little bit higher. 240MHz ARM 9 (at91sam9263B) 2.6.32 kernel, with at91_can (and related files) patched with a few important fixes. I would like to move to a recent kernel, but that is not possible right now. I am considering protecting tx objects as Wolfgang suggests in the pch_can thread. Any ideas? best regards, Henrik Bork Steffensen