From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754779Ab0A0XyS (ORCPT ); Wed, 27 Jan 2010 18:54:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754569Ab0A0XyQ (ORCPT ); Wed, 27 Jan 2010 18:54:16 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:51552 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754528Ab0A0XyO (ORCPT ); Wed, 27 Jan 2010 18:54:14 -0500 Date: Wed, 27 Jan 2010 15:54:23 -0800 (PST) Message-Id: <20100127.155423.169231741.davem@davemloft.net> To: shemminger@vyatta.com Cc: mbreuer@majjas.com, jarkao2@gmail.com, akpm@linux-foundation.org, flyboy@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, mchan@broadcom.com, pcnet32@verizon.net, romieu@fr.zoreil.com, mcarlson@broadcom.com Subject: Re: Hang: 2.6.32.4 sky2/DMAR From: David Miller In-Reply-To: <20100127094531.53c85aa7@nehalam> References: <20100127085049.5b5048e9@nehalam> <4B60707F.1000608@majjas.com> <20100127094531.53c85aa7@nehalam> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) 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 From: Stephen Hemminger Date: Wed, 27 Jan 2010 09:45:31 -0800 > Setting it to 1 causes driver to never go through the dma_sync_single/memcpy > path. Perhaps the code for DMAR doesn't do dma_sync_single_for_cpu > properly, or the value passed to sync_single_for_cpu doesn't account for > all the overhead of padding and/or ether header. For the millionth time... DMAR does not implement any of the DMA SYNC operations, they are set to NULL in the dma ops vector, and thus are NOPs.