From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964911AbbLRRTE (ORCPT ); Fri, 18 Dec 2015 12:19:04 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:48384 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932287AbbLRRTB convert rfc822-to-8bit (ORCPT ); Fri, 18 Dec 2015 12:19:01 -0500 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Julian Margetson Cc: Andy Shevchenko , Tejun Heo , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] ata: sata_dwc_460ex: use "dmas" DT property to find dma channel References: <1450221935-6034-1-git-send-email-mans@mansr.com> <1450364395.30729.136.camel@linux.intel.com> <1450367702.30729.146.camel@linux.intel.com> <1450371184.30729.175.camel@linux.intel.com> <5672F77F.4010306@candw.ms> <567302E8.5050303@candw.ms> <5673061A.4070700@candw.ms> <56732C04.9040100@candw.ms> <5673F277.2050607@candw.ms> <1450441395.30729.203.camel@linux.intel.com> <5674271B.9090308@candw.ms> Date: Fri, 18 Dec 2015 17:18:53 +0000 In-Reply-To: <5674271B.9090308@candw.ms> (Julian Margetson's message of "Fri, 18 Dec 2015 11:32:43 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Julian Margetson writes: > On 12/18/2015 8:49 AM, Måns Rullgård wrote: >> Andy Shevchenko writes: >> >>>>> [ 5.206125] Unable to handle kernel paging request for data at >>>>> address 0x00000000 >>>>> [ 5.228546] Faulting instruction address: 0xc043a2c8 >>>>> [ 5.248577] Vector: 300 (Data Access) at [eddafae0] >>>>> [ 5.268658] pc: c043a2c8: sata_dwc_qc_issue+0xb8/0x204 >>>> Well, that's not good. Can you translate that address to a line of >>>> code? >>> Besides that, can you enable DYNAMIC_DEBUG in the config and append >>> 'dw_dmac_core.dyndbg dw_dmac.dyndbg' to the kernel cmdline? >> Enabling debug messages in the sata_dwc driver might also be informative. >> > Changed the sata-dwc to a module . > > [ 18.475140] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL > [ 18.535698] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL That's strange. The only way that can happen is if dmaengine_prep_slave_sg() return NULL, and that really shouldn't be happening. Did you turn on debug messages in dw_dma? You can enable some extra debug messages by adding "#define VERBOSE_DEBUG" at the top of drivers/dma/dw/core.c -- Måns Rullgård