From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: unexpected scsi timeout Date: Wed, 25 Jul 2007 16:42:37 +0900 Message-ID: <46A6FEED.2050403@gmail.com> References: <46A0A462.2090407@sw.ru> <46A5B632.8040201@gmail.com> <46A5CF7B.40102@sw.ru> <46A6E4A4.6080608@tw.ibm.com> <46A6FD8E.7090803@sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0506.google.com ([64.233.162.231]:13696 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752059AbXGYHmo (ORCPT ); Wed, 25 Jul 2007 03:42:44 -0400 Received: by nz-out-0506.google.com with SMTP id s18so101488nze for ; Wed, 25 Jul 2007 00:42:43 -0700 (PDT) In-Reply-To: <46A6FD8E.7090803@sw.ru> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Vasily Averin Cc: albertl@mail.com, Jeff Garzik , linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, devel@openvz.org Vasily Averin wrote: > Albert Lee wrote: >>>> Vasily Averin wrote: >>>>> I've noticed that some scsi commands for DVD-drive attached to pata_via >>>>> successfully finishes without any delays but reports about TIMEOUT condition. It >>>>> happens because of ATA_ERR bit is set in status register. As result for each >>>>> command Error Handler thread awakened, requests sense buffer and go to sleep again. >>>> Need more info. Please post boot dmesg and the result of 'lspci -nn' >>>> and 'hdparm -I /dev/srX' and when such errors occur. >> Your log looks ok. It's normal for TEST_UNIT_READY to return ATA_ERR when no disc >> inside and libata EH triggered to request sense. > > It's a bit strange for me, IMHO other scsi drivers requests sense buffer without > EH thread assistance. > Currently we know that ATA_ERR can be returned; it is not error, but one of > expected responses. Why we cannot request sense without EH? I would like to > understand is it implementation drawback or I missed something probably? That was a design choice. It's easier to implement that way. -- tejun