From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libata: skip reset on bus not a device Date: Mon, 09 Oct 2006 16:57:00 +0900 Message-ID: <452A00CC.4080205@gmail.com> References: <215036450609292206pd16c7cxa1c5c77ee52c050e@mail.gmail.com> <451E7BD2.7020002@gmail.com> <215036450609301849h64551749uf6b4a3e48c57fe15@mail.gmail.com> <4529BCC4.8060906@gmail.com> <215036450610082354q34b906bdp54a3b9cee52a5855@mail.gmail.com> <4529F391.3030504@gmail.com> <20061009070652.GE10832@htj.dyndns.org> <215036450610090044n56ec3a9dg62573a16d63ab00c@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from nf-out-0910.google.com ([64.233.182.189]:43665 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S932336AbWJIH5K (ORCPT ); Mon, 9 Oct 2006 03:57:10 -0400 Received: by nf-out-0910.google.com with SMTP id x30so1887991nfb for ; Mon, 09 Oct 2006 00:57:09 -0700 (PDT) In-Reply-To: <215036450610090044n56ec3a9dg62573a16d63ab00c@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Joe Jin Cc: linux-ide@vger.kernel.org, lkml , Jeff Garzik Joe Jin wrote: >> > It's against libata development tree. So, you downloaded the tar.gz >> and >> > tested it? > > no, but at latest kernel 2.6.19-rc1 use the same tree as you said, and > it also can worked I see. It's irrelevant anyway. >> And, one more thing to try. The following patch should fix your >> problem. It's against v2.6.18. >> > > while applied the patch, error info gone :) > > A question: if the status register return 0xFF means the device not exist? > why not use ata_devchk()? Many SATA controllers emulate TF registers and pass devchk even when no device is attached. I don't know whether the two conditions can happen together - 0xFF status is usually seen on PATA. Anyways, it's more reliable to test 0xFF. Also, that's what driver/ide has been doing for a long long time and we don't want to deviate from it if possible. -- tejun