From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 12 Sep 2002 02:54:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 12 Sep 2002 02:54:25 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:56808 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id ; Thu, 12 Sep 2002 02:54:24 -0400 Date: Thu, 12 Sep 2002 08:59:03 +0200 From: Jens Axboe To: Paul Mackerras Cc: Benjamin Herrenschmidt , linux-kernel@vger.kernel.org Subject: Re: [PATCH] highmem I/O for ide-pmac.c Message-ID: <20020912065903.GM30234@suse.de> References: <20020911130209.GL1089@suse.de> <20020911185315.530@192.168.4.1> <20020911180502.GD1089@suse.de> <15744.14859.966809.289502@argo.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15744.14859.966809.289502@argo.ozlabs.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 12 2002, Paul Mackerras wrote: > Jens Axboe writes: > > > The above refers to ide_toggle_bounce() export, pmac_* variant is > > exactly the same. Sorry if that wasn't clear. > > Why does ide_toggle_bounce assume we can only do DMA to highmem if > drive->media == ide_disk? At the moment I can't see any reason why > the ide-pmac interface can't do DMA to highmem for a cdrom, for > instance. Because it requires changes to the personality driver (ie ide-disk, ide-cd, etc). I only did those changes to ide-disk, didn't figure it was worthwhile to do for ide-cd for instance. It's not exactly a high-performance media :-) If the device is always in dma mode, no changes are needed. It's when you drop to pio the problem arises, and all the interrupt handlers need to be fixed. -- Jens Axboe