Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 6 Dec 2001 05:00:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 6 Dec 2001 05:00:06 -0500 Received: from jurassic.park.msu.ru ([195.208.223.243]:19973 "EHLO jurassic.park.msu.ru") by vger.kernel.org with ESMTP id ; Thu, 6 Dec 2001 04:59:52 -0500 Date: Thu, 6 Dec 2001 12:59:35 +0300 From: Ivan Kokshaysky To: Kurt Garloff , Linux kernel list Subject: Re: IDE DMA on AXP & barriers Message-ID: <20011206125935.A3930@jurassic.park.msu.ru> In-Reply-To: <20011206061315.J13427@garloff.etpnet.phys.tue.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20011206061315.J13427@garloff.etpnet.phys.tue.nl>; from garloff@suse.de on Thu, Dec 06, 2001 at 06:13:15AM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 06, 2001 at 06:13:15AM +0100, Kurt Garloff wrote: > I would imagine that the following barriers are nacessary: > * After setting up the IDE DMA tables (PRD) and having the data there, > we need to have a barrier before telling the controller to do DMA. Actually, we have more than one - the memory barriers are hidden in outX() macros. > * After the controller is done with it, we need to make sure the > data is in mem before we use it (i.e. we need some mb() equiv on the > controller) Sure, otherwise the controller just wouldn't work, and not only on alpha. I never had any problems with IDE DMA on lx164 (which has exactly the same IDE chip), but it was back in 2.3 or 2.4-test times... Maybe something got broken since then - I could check this (if I find a spare IDE drive). Ivan. - 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/