From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751028AbVLZGFE (ORCPT ); Mon, 26 Dec 2005 01:05:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751032AbVLZGFE (ORCPT ); Mon, 26 Dec 2005 01:05:04 -0500 Received: from zproxy.gmail.com ([64.233.162.194]:19586 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S1751028AbVLZGFD convert rfc822-to-8bit (ORCPT ); Mon, 26 Dec 2005 01:05:03 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=aJCcNwg2sWEQcaPgeSk4QhGXKWBfvOJPoYGC9pSBSFQVxKTFmhMEJUVhljLdc05TQ1WAm6uHGS7IrFlKmjT+fZwMoti+bRl21rVVB5EvsopZkrUTdQrri5Nwlc8KAbGnOrFxeiVh2fcS6qEEaZk6JwHQMBAjSPU4ML6eBe3hRi4= Message-ID: <7a37e95e0512252205t68c6b6f6sfeedf3a75880fda9@mail.gmail.com> Date: Mon, 26 Dec 2005 11:35:00 +0530 From: Deven Balani To: linux-kernel@vger.kernel.org Subject: Ping-Pong Compatible DMA buffer chaining MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi All! I am developing a SATA Driver which is libata-complaint for ARM platform for linux-2.4 kernels. But I am facing these issues: 1) The SATA Host Controller supports a DMA Logic which has Ping Pong Buffers. How Can I allocate a linear contiguous buffer and give it to the Buffer Descriptors of the Host Controller. I believe consistent alloc would help me in this regard. But How could I do a chaining of Buffers in a Ping Pong Scenario which has Buffer Descriptors. 2) The libata is using Scatter-Gather List to send Device Identify Command. Is it necessary to have a Scatter-Gather List for non-PCI ARM platforms. Can I bypass this mechanism. Thanks, Deven