From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753765AbYAUR3f (ORCPT ); Mon, 21 Jan 2008 12:29:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751583AbYAUR3Z (ORCPT ); Mon, 21 Jan 2008 12:29:25 -0500 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:33983 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751109AbYAUR3Y (ORCPT ); Mon, 21 Jan 2008 12:29:24 -0500 Date: Mon, 21 Jan 2008 17:27:15 +0000 From: Alan Cox To: Tejun Heo Cc: Andrew Morton , Georgi Chulkov , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Mark Lord Subject: Re: ATA device reset, shoud I be concerned? Message-ID: <20080121172715.0e3e5e4d@lxorguk.ukuu.org.uk> In-Reply-To: <4794D020.4060204@gmail.com> References: <200801140019.20668.g.chulkov@jacobs-university.de> <20080115025435.1e21b703.akpm@linux-foundation.org> <20080115113552.75731bf8@lxorguk.ukuu.org.uk> <4794501E.90306@gmail.com> <20080121130256.2443d7c1@lxorguk.ukuu.org.uk> <47949AA4.9090601@gmail.com> <20080121141425.45aa9c61@lxorguk.ukuu.org.uk> <4794ACAF.70505@gmail.com> <20080121164744.2f7d0ed1@lxorguk.ukuu.org.uk> <4794D020.4060204@gmail.com> X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.3; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I still don't think it's worth the trouble. There's currently only one > reported device which forgets to raise IRQ on media error. The behavior Most people wouldn't realise what is going on. > > Old IDE says it works for PATA. For SATA I can see it might need more > > care and you might simply not be able to get the info. > > Old IDE often locks up the machine hard after timeouts. I'm all for The code paths are racy - it didn't use to in 2.4 (except for the promise drain bug) > gathering more info but benefit vs. risk equation just doesn't look good > here. Why take risk for a rare device which forgets to raise IRQ on > media error? If such behavior is wide spread among PATA drives && we > can verify that TF register access after timeout is safe for PATA > controllers, sure, but currently we aren't sure about either. We lose IRQs in lots of other cases. Promise PATA is particularly bad at forgetting to give us the completion interrupt. Alan