Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751394AbWAKJ3M (ORCPT ); Wed, 11 Jan 2006 04:29:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751395AbWAKJ3L (ORCPT ); Wed, 11 Jan 2006 04:29:11 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:10055 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S1751394AbWAKJ3K (ORCPT ); Wed, 11 Jan 2006 04:29:10 -0500 Date: Wed, 11 Jan 2006 10:29:38 +0100 From: Jens Axboe To: Andrey Borzenkov Cc: Chuck Ebbert <76306.1226@compuserve.com>, linux-kernel Subject: Re: [PATCH]trivial: add CDC_RAM to ide-cd capabilities mask Message-ID: <20060111092937.GS3389@suse.de> References: <200601110327_MC3-1-B5A3-6E0F@compuserve.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1823 Lines: 55 On Wed, Jan 11 2006, Andrey Borzenkov wrote: > > > > drive name: sr0 > > drive speed: 1 > > drive # of slots: 1 > > Can close tray: 1 > > Can open tray: 1 > > Can lock tray: 1 > > Can change speed: 0 > > Can select disk: 0 > > Can read multisession: 1 > > Can read MCN: 1 > > Reports media changed: 1 > > Can play audio: 1 > > Can write CD-R: 0 > > Can write CD-RW: 0 > > Can read DVD: 0 > > Can write DVD-R: 0 > > Can write DVD-RAM: 0 > > Can read MRW: 1 > > Can write MRW: 1 > > Can write RAM: 1 > > > > There's no way this drive knows anything about MRW or random-access writing: > > > ... > > And an ATAPI DVD-ROM also reports (before the above patch): > > > > Can read MRW: 1 > > Can write MRW: 1 > > Can write RAM: 1 > > > > I know. There were patches from Jens for both 2.4 and 2.6 that add MRW > support to ide-cd for sure; may be for sr too, am not sure. Jens, any > reasons for them not in mainstream? Otherwise probably ide-cd and sr should > not announce MRW capabiliies at all, it is too confusing; I'll send a patch > when I am at home. MRW support is in 2.6 since ages. The MRW flag is only detected on open, so it should disappear from the proc file once you have opened the drive. It has to be done that way, I'm afraid. Other than that, it's not uncommon for the cap probe to fail somewhat on older drives. So the 'info' file isn't always 100% reliable. -- Jens Axboe - 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/