Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752861AbYCPRxQ (ORCPT ); Sun, 16 Mar 2008 13:53:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751278AbYCPRxE (ORCPT ); Sun, 16 Mar 2008 13:53:04 -0400 Received: from fk-out-0910.google.com ([209.85.128.189]:46958 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165AbYCPRxC (ORCPT ); Sun, 16 Mar 2008 13:53:02 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:cc:references:in-reply-to:mime-version:content-disposition:message-id:content-type:content-transfer-encoding; b=SCuwZ0Hdy+/d2Y2vnmc+px7J2uzK9Xx7s6lTr2dqPCsCmotWcloBuKUyjoXqQNyjOSL0j/AjUM/qI4Z9MTGvkHdZmoYoHOJbVzyT9TZzu77rzvz7uci3oGZN/mYhICenCgMtakRhW1zSvRhHLYudjQglFdxfXv7ufT9hFszmk/M= From: Bartlomiej Zolnierkiewicz To: Linus Torvalds Subject: Re: Linux 2.6.25-rc4 Date: Sun, 16 Mar 2008 19:07:04 +0100 User-Agent: KMail/1.9.9 Cc: Anders Eriksson , "Rafael J. Wysocki" , Jens Axboe , Ingo Molnar , Linux Kernel Mailing List References: <20080316140118.891732DC044@tippex.mynet.homeunix.org> In-Reply-To: MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200803161907.04581.bzolnier@gmail.com> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2434 Lines: 63 On Sunday 16 March 2008, Linus Torvalds wrote: > > On Sun, 16 Mar 2008, Anders Eriksson wrote: > > > > Many bisects later, now with taking care of making 'make oldconfig' off a > > known good config for each iteration, and doing 10 reboots and 5 smartd > > invocations for each version deemed good (not that anyone failed midway). > > Ok, this is interesting. It's clearly a regression, so we need to undo it. > However, it's not trivial to revert, since lots of things have changed > around that area since. > > In particular, commit 7267c3377443322588cddaf457cf106839a60463 ("ide: > remove REQ_TYPE_ATA_CMD") ended up removing the whole drive_cmd_intr() > function, because now all the commands are handled with the > REQ_TYPE_ATA_TASKFILE model instead, which uses a whole another path. > > And quite frankly, I think the commit you bisected to really is very > broken. It starts doing error handling *before* it has handled the DRQ > bit, and that's bogus, since iirc a lot of controllers need to have their > DRQ issues satisfied before anything else. We don't do error handling for special commands (REQ_TYPE_ATA_*) at all, ide_error() just dumps device's status/error register(s) and finishes early: ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat) { struct request *rq; u8 err; err = ide_dump_status(drive, msg, stat); if ((rq = HWGROUP(drive)->rq) == NULL) return ide_stopped; /* retry only "normal" I/O: */ if (!blk_fs_request(rq)) { rq->errors = 1; ide_end_drive_cmd(drive, stat, err); return ide_stopped; } [ Yeah, I completely agree that it needs some re-design but I don't see how it can be related to the problem experienced by Anders. ] > So what probably happens is that yes, you get an error, but the IDE drive This is unlikely as we should get some error message from ide_dump_status() and we are not getting any (Anders, please correct me if I'm wrong). Moreover the problem was initially narrowed down to commit 852738f39258deafb3d89c187cb1a4050820d555 which is two commits _before_ the one that we are currently discussing. I think that we are looking into completely wrong direction... Thanks, Bart -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/