Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758885AbXEJLRS (ORCPT ); Thu, 10 May 2007 07:17:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754385AbXEJLRM (ORCPT ); Thu, 10 May 2007 07:17:12 -0400 Received: from mx1.cdac.in ([203.199.132.35]:4710 "EHLO mx1.cdac.in" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753640AbXEJLRL (ORCPT ); Thu, 10 May 2007 07:17:11 -0400 Message-ID: <4642FFA7.4040303@cdac.in> Date: Thu, 10 May 2007 16:49:03 +0530 From: Mahesh User-Agent: Thunderbird 1.5.0.4 (Windows/20060516) MIME-Version: 1.0 To: David Miller CC: linux-kernel@vger.kernel.org, kernelnewbies@nl.linux.org Subject: Re: [HOWTO] accessing the DMA mapped data References: <4642D095.6070305@cdac.in> <20070510.014751.74749340.davem@davemloft.net> In-Reply-To: <20070510.014751.74749340.davem@davemloft.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-imss-version: 2.046 X-imss-result: Passed X-imss-scanInfo: M:P L:E SM:0 X-imss-tmaseResult: TT:0 TS:0.0000 TC:00 TRN:0 TV:3.6.1039(15166.003) X-imss-scores: Clean:80.46452 C:2 M:3 S:5 R:5 X-imss-settings: Baseline:2 C:1 M:1 S:1 R:1 (0.1500 0.1500) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 754 Lines: 22 Hi Miller, Thanks for replying. > You can eithe keep track of this yourself, or (depending upon > your usage) you might be able to use DMA pools, see > dma_pool_create() and friends. > I think you have not understood my question properly. My problem is, the layer above the driver will do dma_map_single on a kmalloc'ed buffer and passes the result (bus address) to the device driver. Now the driver has to modify the contents of the the original buffer. Is it possible to do that ?? -regards, Mahesh - 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/