From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759056AbXKLTLa (ORCPT ); Mon, 12 Nov 2007 14:11:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751250AbXKLTLW (ORCPT ); Mon, 12 Nov 2007 14:11:22 -0500 Received: from rtr.ca ([76.10.145.34]:3624 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbXKLTLV (ORCPT ); Mon, 12 Nov 2007 14:11:21 -0500 Message-ID: <4738A558.1040304@rtr.ca> Date: Mon, 12 Nov 2007 14:11:20 -0500 From: Mark Lord User-Agent: Thunderbird 2.0.0.6 (X11/20070728) MIME-Version: 1.0 To: Ron Yorgason Cc: linux-kernel@vger.kernel.org Subject: Re: Better support for Delkin cardbus CF adapters -- IDE layer References: <93d1fdd10711121003t2286493bob25a3acd12134720@mail.gmail.com> In-Reply-To: <93d1fdd10711121003t2286493bob25a3acd12134720@mail.gmail.com> 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 Ron Yorgason wrote: > But I'm concerned about performance. The delkin_cb.c file states: > > * This is slightly peculiar, in that it is a PCI driver, > * but is NOT an IDE PCI driver -- the IDE layer does not directly > * support hot insertion/removal of PCI interfaces, so this driver > * is unable to use the IDE PCI interfaces. Instead, it uses the > * same interfaces as the ide-cs (PCMCIA) driver uses. > * On the plus side, the driver is also smaller/simpler this way. > > > My attempts to use hdparm to turn on DMA for my device have failed. I > assume this means DMA is not currently supported. In my tests, read > support seems fast enough, but writing maxes out around 2MB/s. And if > there is a lot of reading and writing going on (ie, trying to compile > the kernel), performance is pretty abysmal. What would it take to get > proper DMA support? Is it an architecture problem, in that this > doesn't use the normal IDE PCI driver? Is it a lack of documentation > on card specs? What can I do to help? .. The problem is total lack of documentation. If you can find some docs, then we can fully support it, both in old IDE (as current), and in the newer libata (not there at all now). Cheers