From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [BUG] libahci returns stale result tf much of the time. Date: Mon, 04 Oct 2010 15:42:14 -0400 Message-ID: <4CAA2E16.4010905@pobox.com> References: <4C9C3878.9010206@teksavvy.com> <4C9C44D0.1030409@teksavvy.com> <4C9CA385.5090709@teksavvy.com> <4C9CA673.4090104@teksavvy.com> <4C9D33C0.8050900@gmail.com> <4CA99BCB.8080904@gmail.com> <4CAA0885.8060906@teksavvy.com> <4CAA0996.5080403@teksavvy.com> <4CAA0F6C.6080609@teksavvy.com> <4CAA21F4.5060000@teksavvy.com> <4CAA2AA6.2010204@pobox.com> <4CAA2C6F.2090603@teksavvy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qw0-f46.google.com ([209.85.216.46]:34772 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932499Ab0JDTmR (ORCPT ); Mon, 4 Oct 2010 15:42:17 -0400 Received: by qwh6 with SMTP id 6so3297383qwh.19 for ; Mon, 04 Oct 2010 12:42:17 -0700 (PDT) In-Reply-To: <4CAA2C6F.2090603@teksavvy.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Lord Cc: Tejun Heo , Robert Hancock , Seed , IDE/ATA development list On 10/04/2010 03:35 PM, Mark Lord wrote: > On 10-10-04 03:27 PM, Jeff Garzik wrote: >> On 10/04/2010 02:50 PM, Mark Lord wrote: >>> I've dug a bit deeper, and worked around the issue. >>> It seems that libata is not always happy about DATA-xfer commands >>> that also have the check-sense bit set (0x20 in cdb[2]). >>> Perhaps that's not even valid in SCSI ?? >> >> >> Very interesting... poking at this now on pre- and post-libahci >> platforms. As you said, don't see much difference in behavior WRT >> libahci -- which I expected/hoped, since that split shouldn't have >> changed behavior at all[1]. > > > Yeah. Non-data commands still get a (correct) updated result_tf from AHCI, > but data commands don't get one, unless they fail. > > Weird, but I've worked around it now. Might be that we just get a single-bit "OK" notification from hardware for successfully completed commands, a la NCQ's SDB FIS. Which opcodes are you using? I see set-acoustic-mgmt in one email... Jeff