From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753931Ab1LIOAG (ORCPT ); Fri, 9 Dec 2011 09:00:06 -0500 Received: from mail.karo-electronics.de ([81.173.242.67]:49829 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045Ab1LIOAD (ORCPT ); Fri, 9 Dec 2011 09:00:03 -0500 Message-ID: <20194.5210.650914.867608@ipc1.ka-ro> Date: Fri, 9 Dec 2011 14:59:54 +0100 From: =?utf-8?Q?Lothar_Wa=C3=9Fmann?= To: Marc Kleine-Budde Cc: Wolfgang Grandegger , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH] flexcan: Acknowledge all interrupt sources in the IRQ handler In-Reply-To: <4EE212AE.40005@pengutronix.de> References: <1323438454-6816-1-git-send-email-LW@KARO-electronics.de> <4EE212AE.40005@pengutronix.de> X-Mailer: VM 8.0.9 under Emacs 22.2.1 (i486-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Marc Kleine-Budde writes: > On 12/09/2011 02:47 PM, Lothar Waßmann wrote: > > Otherwise the handler will get stuck in an endless IRQ loop when an > > interrupt condition occurs that is not being acked (e.g. TWRN) > > On which CPU do you have this problem? > on i.MX28. > Seems that mx25/35 behave a bit different than mx28. But I had no time > to dig into this, yet. BTW Wolfgang is just reworking error handling, > can you please test his patches he recently posted on linux-can. > The ESR of i.MX25 is completely identical to the i.MX28. You should be able to reproduce the problem when trying to send a message to a CAN interface with the transceiver disabled. You will get a BIT0_ERR and the TWRN bit will be asserted and never cleared leading to an endless interrupt loop. Lothar Waßmann -- ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstraße 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Geschäftsführer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info@karo-electronics.de ___________________________________________________________