From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 06/11] de2104x: fix DMA sync_single length error Date: Thu, 21 Jan 2010 17:12:09 -0800 Message-ID: <20100121171209.1e8eb864@nehalam> References: <20100120204459.820265084@vyatta.com> <20100120204559.177544514@vyatta.com> <20100122010244.GA27529@lackof.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: David Miller , Jarek Poplawski , Grant Grundler , netdev@vger.kernel.org To: Grant Grundler Return-path: Received: from mail.vyatta.com ([76.74.103.46]:38313 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754962Ab0AVBMV (ORCPT ); Thu, 21 Jan 2010 20:12:21 -0500 In-Reply-To: <20100122010244.GA27529@lackof.org> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 21 Jan 2010 18:02:44 -0700 Grant Grundler wrote: > On Wed, Jan 20, 2010 at 12:45:05PM -0800, Stephen Hemminger wrote: > > The DMA api requires that the full mapping be sync'd when > > copying frame. First found by Jarek on sky2. > > Are you referring to the example code in Documentation/PCI/PCI-DMA-mapping.txt? > > I don't see any "Use the full mapping" statement otherwise. > > Is there a DMA HW implementation that requires the syncing full buffer? > > I think it would be interesting to point that out in the commit comments > since other NIC drivers are likely to also have this issue as well. > > I have no objection to this patch. Just want to be clear why > it's being pushed. > > Please added Acked-by: Grant Grundler The documentation was in DMA-API.txt and it was wrong. The DMA debug library was enforcing a bogus restriction. Dave correctly dropped the patch.