From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Thompson Subject: Re: 2.6.20 libata cdrom Date: Tue, 1 May 2007 13:21:17 -0400 Message-ID: <20070501172117.GA20328@electro-mechanical.com> References: <20070427175205.GD7809@electro-mechanical.com> <4635C35D.1020807@gmail.com> <20070430202107.GF5942@electro-mechanical.com> <4636C2C7.8090206@gmail.com> <20070501121703.GH5942@electro-mechanical.com> <46373AEE.6070908@rtr.ca> <20070501131818.GA18521@electro-mechanical.com> <46374354.7040307@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.electro-mechanical.com ([216.184.71.30]:53092 "EHLO mail.electro-mechanical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754955AbXEARVU (ORCPT ); Tue, 1 May 2007 13:21:20 -0400 Content-Disposition: inline In-Reply-To: <46374354.7040307@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Mark Lord , linux-kernel@vger.kernel.org, IDE/ATA development list , albertcc@tw.ibm.com, Jeff Garzik On Tue, May 01, 2007 at 03:40:36PM +0200, Tejun Heo wrote: > >> Tejun, don't we have a fallback for when IDENTIFY fails? > >> If the drive rejects it (err=0x04), then this can mean only one thing: > >> unsupported command, so we next must try PACKET_IDENTIFY. > > Up until now, we've been depending on the device giving us the correct > signature on reset. This is the first reported case which screws that > up. Gee... Two crazy screwed up devices today. What's going on? libata-pata is getting it's field testing now! > > Is it doing that just for this drive? I use libata on another machine (Dell > > Dimension 2400) and it finds the cdrom just fine. > > That specific cdrom is crazy. It's telling libata that it's a disk when > it apparently isn't. Wasn't sure, I thought it was something with the chipset. Every Dell Dimension L series machine has done this to me (The DMA thing, that is). Some gateways have as well. > > The one thing I do know, the machine with the non-working libata cdrom also > > does not work with the ide driver *ONLY IF* DMA is turned on. > > This is probably as Mark explained in the other thread. > > Anyways, oh well, it looks like we need fallback mechanism to the other > IDENTIFY command after all. Jeff, any ideas or objections? Got a patch or anything I can do to test?