From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: [PATCH] libata: workaround DRQ=1 ERR=1 for ATAPI tape drives Date: Tue, 13 Nov 2007 09:16:30 -0500 Message-ID: <4739B1BE.7080109@rtr.ca> References: <471C6C44.2030607@gmail.com> <471CEDD4.5040201@garzik.org> <471D25D0.9020702@rtr.ca> <47397784.9070205@tw.ibm.com> <47397CC0.1070401@tw.ibm.com> <4739AB5B.7000703@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:2271 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753839AbXKMOQb (ORCPT ); Tue, 13 Nov 2007 09:16:31 -0500 In-Reply-To: <4739AB5B.7000703@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: albertl@mail.com Cc: Jeff Garzik , Tejun Heo , linux-ide@vger.kernel.org, Alan Cox Mark Lord wrote: > .. > NAK. There's no guarantee that the next command after an error > will always be REQUEST_SENSE. Or is there? > > I think we should just ignore the ERR bit when DRQ is set for PACKET > command. > Period. Possibly only for tape drives (since they all seem to do this), > and maybe not for non-tape drives. .. Note also that if we already *know* that this ia an ATAPI device, then we *know* that it will accept the PACKET opcode without error, so there is no reason to even look at the ERR bit until after the packet CDB has been transferred. But I still think this should only apply to tapes for now.