Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756047AbZAJLuT (ORCPT ); Sat, 10 Jan 2009 06:50:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753095AbZAJLuD (ORCPT ); Sat, 10 Jan 2009 06:50:03 -0500 Received: from h155.mvista.com ([63.81.120.155]:63167 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752200AbZAJLuC (ORCPT ); Sat, 10 Jan 2009 06:50:02 -0500 Message-ID: <49688B63.5030105@ru.mvista.com> Date: Sat, 10 Jan 2009 14:49:55 +0300 From: Sergei Shtylyov User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: Christian Borntraeger Cc: Alan Cox , 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() References: <200901091334.55823.borntraeger@de.ibm.com> <200901101009.13699.borntraeger@de.ibm.com> <20090110104114.633cacd8@lxorguk.ukuu.org.uk> <200901101242.05203.borntraeger@de.ibm.com> In-Reply-To: <200901101242.05203.borntraeger@de.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1628 Lines: 46 Hello. Christian Borntraeger wrote: >>> 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 ? >> > > I instrumented __atapi_pio_bytes to print some variables. This is the dump of > the first two: > > [ 1.484730] count: 36 sg->length: 36 qc->cursg_ofs: 0 bytes: 36 > [ 1.485709] qc->cdb[]:12000000240000000000000000000000 > That works fine. > That's the typical INQUIRY command with 36-byte data length. > [ 1.499843] scsi 1:0:0:0: CD-ROM HL-DT-ST DVDRAM GSA-U10N 1.05 PQ: 0 ANSI: 5 > [ 1.508389] count: 18 sg->length: 96 qc->cursg_ofs: 0 bytes: 18 > [ 1.509369] qc->cdb[]:03000000600000000000000000000000 > That one is broken. > That's the typical REQUEST SENSE command with 18-byte data length. MBR, Sergei -- 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/