Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756667Ab0LQWpu (ORCPT ); Fri, 17 Dec 2010 17:45:50 -0500 Received: from hqemgate03.nvidia.com ([216.228.121.140]:12833 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755954Ab0LQWpq (ORCPT ); Fri, 17 Dec 2010 17:45:46 -0500 X-PGP-Universal: processed; by hqnvupgp05.nvidia.com on Fri, 17 Dec 2010 14:37:04 -0800 Date: Fri, 17 Dec 2010 14:44:29 -0800 From: rmorell@nvidia.com To: Greg KH Cc: David Brownell , Benoit Goby , Alan Stern , Sarah Sharp , Matthew Wilcox , Ming Lei , Jacob Pan , Olof Johansson , Erik Gilling , Colin Cross , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC] Align tegra-ehci DMA transfers to 32B Message-ID: <20101217224429.GF25105@morell.nvidia.com> References: <1292623129-26361-1-git-send-email-rmorell@nvidia.com> <20101217223227.GA19418@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101217223227.GA19418@suse.de> X-NVConfidentiality: public User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1399 Lines: 33 On Fri, Dec 17, 2010 at 02:32:27PM -0800, Greg KH wrote: > On Fri, Dec 17, 2010 at 01:58:47PM -0800, Robert Morell wrote: > > This small set of patches fixes an issue where DMA from the tegra EHCI > > controller could be corrupted. It was most commonly seen with USB network > > adapters, though in theory it could happen with any USB traffic. > > > > (Note: An attempt was made to fix this with commit 367c3aab, which set > > NET_IP_ALIGN to 0 and NET_SKB_PAD to 32. Unfortunately, not all network > > drivers honor them (presumably since these are intended as optimizations rather > > than hard rules). This does mean that properly-written network drivers should > > fall through this code with very little overhead, however.) > > We don't have many USB network drivers, why not just fix them up to > handle this properly, then you will not need to change any core USB > code, right? The USB core code is used by devices other than USB adapters. We've only seen this problem so far with usbnet devices, but I can't test every USB device ever to make sure that they always align their DMA to 32 bytes. Thanks, Robert > thanks, > > greg k-h > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/