From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [BUG] libahci returns stale result tf much of the time. Date: Tue, 05 Oct 2010 18:06:01 +0200 Message-ID: <4CAB4CE9.9070709@gmail.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> <4CAA2E16.4010905@pobox.com> <4CAA3033.8030405@teksavvy.com> <4CAACEBE.1000104@gmail.com> <4CAB30FA.2010508@teksavvy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:57728 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755121Ab0JEQEG (ORCPT ); Tue, 5 Oct 2010 12:04:06 -0400 Received: by fxm4 with SMTP id 4so515641fxm.19 for ; Tue, 05 Oct 2010 09:04:05 -0700 (PDT) In-Reply-To: <4CAB30FA.2010508@teksavvy.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Lord Cc: Jeff Garzik , Robert Hancock , Seed , IDE/ATA development list Hello, On 10/05/2010 04:06 PM, Mark Lord wrote: > Yeah, maybe something like that. > > But do note that I have verified that "hdparm -C" does work correctly, > and is dependent upon correctly returned result_tf values. > > It's not a PIO "data" command, though. Does it get issued the same way? PIO Setup FIS is not used for nodata commands. IIRC, nodata uses D2H Reg FIS for command completion. I think the only exception is PIO data commands. The weird hack is to satisfy PIO data command protocol timing requirement stemming from PATA specification. Eh... ugly. Thanks. -- tejun