From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261415AbUL0AI4 (ORCPT ); Sun, 26 Dec 2004 19:08:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261416AbUL0AI4 (ORCPT ); Sun, 26 Dec 2004 19:08:56 -0500 Received: from a26.t1.student.liu.se ([130.236.221.26]:7574 "EHLO mail.drzeus.cx") by vger.kernel.org with ESMTP id S261415AbUL0AIz (ORCPT ); Sun, 26 Dec 2004 19:08:55 -0500 Message-ID: <41CF528C.7090003@drzeus.cx> Date: Mon, 27 Dec 2004 01:08:44 +0100 From: Pierre Ossman User-Agent: Mozilla Thunderbird 0.9 (X11/20041127) X-Accept-Language: en-us, en MIME-Version: 1.0 To: LKML CC: alan@lxorguk.ukuu.org.uk, Tommy.Reynolds@MegaCoder.com Subject: ISA DMA demand mode (again) X-Enigmail-Version: 0.89.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org A few months ago I asked why the linux ISA DMA code is locked to use only single mode but I didn't get much of a response. Now this has move from a curiosity to a necessity for my driver so I'm asking again. Using single mode I get transfer rates of 300 kBps. With demand mode I get 1500 kBps. So you see why I'd like to use demand mode. Side note: If I tell the DMA controller to do single mode and the chip to do demand I get 480 kBps. I find it amazing that it works at all in this case. I included the people who helped me with the wonderful world of ISA DMA (;)) the last time in the hope that you might have some insight into this. Rgds Pierre