From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754852AbYKNWAk (ORCPT ); Fri, 14 Nov 2008 17:00:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751734AbYKNWAa (ORCPT ); Fri, 14 Nov 2008 17:00:30 -0500 Received: from server.drzeus.cx ([85.8.24.28]:56192 "EHLO smtp.drzeus.cx" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751670AbYKNWAa (ORCPT ); Fri, 14 Nov 2008 17:00:30 -0500 Date: Fri, 14 Nov 2008 23:00:26 +0100 From: Pierre Ossman To: Ben Dooks Cc: linux-kernel@vger.kernel.org, sdhci-devel@list.drzeus.cx, Ben Dooks Subject: Re: [patch 6/7] SDHCI: Check DMA for overruns at end of transfer Message-ID: <20081114230026.18513b8a@mjolnir.drzeus.cx> In-Reply-To: <20081103201010.820070757@fluff.org.uk> References: <20081103200944.099353331@fluff.org.uk> <20081103201010.820070757@fluff.org.uk> X-Mailer: Claws Mail 3.6.0 (GTK+ 2.14.4; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 03 Nov 2008 20:09:50 +0000 Ben Dooks wrote: > At the end of a transfer, check that the DMA engine in the > SDHCI controller actually did what it was meant to and didn't > overrun the end of the buffer. > > This seems to be triggered by a timeout during an CMD25 (multiple block > write) to a card. The mmc_block module then issues a command to find out > how much data was moved and this seems to end up triggering this DMA > check. The result is the card's queue generates an OOPS as the stack has > been trampled on due to the extra data transfered. > > Signed-off-by: Ben Dooks I'm sorry, but I don't see how this is anywhere near acceptable. This should be a panic at the very least, and until this can be sorted out and avoided the driver should avoid using DMA on these chips. -- -- Pierre Ossman Linux kernel, MMC maintainer http://www.kernel.org rdesktop, core developer http://www.rdesktop.org WARNING: This correspondence is being monitored by the Swedish government. Make sure your server uses encryption for SMTP traffic and consider using PGP for end-to-end encryption.