Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755325AbZAJKlX (ORCPT ); Sat, 10 Jan 2009 05:41:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753623AbZAJKlN (ORCPT ); Sat, 10 Jan 2009 05:41:13 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:39608 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753442AbZAJKlM (ORCPT ); Sat, 10 Jan 2009 05:41:12 -0500 Date: Sat, 10 Jan 2009 10:41:14 +0000 From: Alan Cox To: Christian Borntraeger Cc: linux-ide@vger.kernel.org, Jeff Garzik , lkml Subject: Re: todays git: WARNING: at drivers/ata/libata-sff.c:1017 ata_sff_hsm_move+0x45e/0x750() Message-ID: <20090110104114.633cacd8@lxorguk.ukuu.org.uk> In-Reply-To: <200901101009.13699.borntraeger@de.ibm.com> References: <200901091334.55823.borntraeger@de.ibm.com> <20090109124412.619330ea@lxorguk.ukuu.org.uk> <200901101009.13699.borntraeger@de.ibm.com> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; 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 Content-Length: 888 Lines: 21 > I did some printk debugging. > __atapi_pio_bytes is called with bytes=18. That means with 32bit transfers > there is a 2 byte trailing transfer, which triggers this WARN_ON. Ouch.. that means all that someone issued a multiple segment data transfer with a 2 byte aligned chunk in the middle. That is a bit of a suprise because we set blk_queue_dma_alignment to 3 so the block layer should never hand us an sg list in that form. That means we've either got a block layer bug or someone somewhere is generating invalid sg lists internally to libata. Can you dump qc->cdb[] and see what command is getting issued in the broken form ? Alan -- 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/