From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert Lee Subject: Re: libata: CD and dvd devices not recognized Date: Fri, 23 Mar 2007 11:21:01 +0800 Message-ID: <4603479D.9070803@tw.ibm.com> References: <45F873AC.6010204@gmail.com> <200703172107.42107.bzolnier@gmail.com> <45FD0F68.7090207@gmail.com> <200703181610.33714.bzolnier@gmail.com> <45FE7DCC.3000507@ru.mvista.com> <45FEE5EB.9020909@gmail.com> <4600BA1C.7060300@tw.ibm.com> <4600F45C.3000303@gmail.com> <46021CDA.3070807@tw.ibm.com> <4602979F.80002@ru.mvista.com> Reply-To: albertl@mail.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e31.co.us.ibm.com ([32.97.110.149]:54576 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422659AbXCWDVb (ORCPT ); Thu, 22 Mar 2007 23:21:31 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e31.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l2N3LUrA015927 for ; Thu, 22 Mar 2007 23:21:30 -0400 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by westrelay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l2N3LUjg045378 for ; Thu, 22 Mar 2007 21:21:30 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l2N3LTQb030175 for ; Thu, 22 Mar 2007 21:21:30 -0600 In-Reply-To: <4602979F.80002@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Sergei Shtylyov Cc: albertl@mail.com, YUP , Bartlomiej Zolnierkiewicz , linux-ide@vger.kernel.org, Jeff Garzik , Alan Cox , Tejun Heo Sergei Shtylyov wrote: > Hello. > > Albert Lee wrote: > >> Thanks for the detailed log. >> It looks like the bad INQUIRY command >> "CDB (4:0,1,0) 12 01 00 00 fe 00 00 00 00" (INQUIRY, length=254, >> EVPD=1) >> is coming from the user space, not the SCSI mid-layer. > > >> I guess two problems together caused this bug: >> 1. Ubuntu Linux issues an incorrect INQUIRY command to the drive. >> (Other distros seem to have the INQUIRY correct.) > > > But what is incorrect about sending INQUIRY with EVPD bit? Nothing wrong from the SCSI point of view. However, in the early ATAPI spec (sff-8020i), this EVPD bit is "reserved". And apprently some imperfect ATAPI CD-ROM drive doesn't handle it well when EVPD = 1. :( Hmm, how about the revised version: 1. Ubuntu Linux issues a correct INQUIRY command to the drive which set EVPD = 1. However, EVPD is "reserved" per early ATAPI spec and the AOpen 56X/AKH drive times out in this case. ... -- albert