From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: [PATCH] flexcan: Acknowledge all interrupt sources in the IRQ handler Date: Fri, 09 Dec 2011 15:35:02 +0100 Message-ID: <4EE21C96.5010604@grandegger.com> References: <1323438454-6816-1-git-send-email-LW@KARO-electronics.de> <4EE212AE.40005@pengutronix.de> <20194.5210.650914.867608@ipc1.ka-ro> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Marc Kleine-Budde , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: =?ISO-8859-1?Q?Lothar_Wa=DFmann?= Return-path: In-Reply-To: <20194.5210.650914.867608@ipc1.ka-ro> Sender: linux-can-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 12/09/2011 02:59 PM, Lothar Wa=DFmann wrote: > Hi, >=20 > Marc Kleine-Budde writes: >> On 12/09/2011 02:47 PM, Lothar Wa=DFmann 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. Yes, it is definitely needed on i.MX28 and I already have it in my series. See: https://gitorious.org/~wgrandegger/linux-can/wg-linux-can-next/commit/8= ad94fa0dd7f7728824fa8fd4479390ac3f189c7 BTW: at similar patch was already sent by Reuben Dowle. >> Seems that mx25/35 behave a bit different than mx28. But I had no ti= me >> 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. If you are right, the code was never working on i.MX25/35... which I do= ubt. Wolfgang.