Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932580AbbLSCe2 (ORCPT ); Fri, 18 Dec 2015 21:34:28 -0500 Received: from mail-yk0-f179.google.com ([209.85.160.179]:32786 "EHLO mail-yk0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752523AbbLSCeZ convert rfc822-to-8bit (ORCPT ); Fri, 18 Dec 2015 21:34:25 -0500 MIME-Version: 1.0 In-Reply-To: References: <1450221935-6034-1-git-send-email-mans@mansr.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> <56745BA4.1090607@candw.ms> <56748D85.4060108@candw.ms> Date: Sat, 19 Dec 2015 04:34:24 +0200 Message-ID: Subject: Re: [PATCH 1/3] ata: sata_dwc_460ex: use "dmas" DT property to find dma channel From: Andy Shevchenko To: =?UTF-8?B?TcOlbnMgUnVsbGfDpXJk?= Cc: Julian Margetson , Andy Shevchenko , Tejun Heo , linux-ide@vger.kernel.org, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5278 Lines: 111 On Sat, Dec 19, 2015 at 1:16 AM, Måns Rullgård wrote: > Julian Margetson writes: > >> On 12/18/2015 6:33 PM, Måns Rullgård wrote: >>> Julian Margetson writes: >>> >>>> On 12/18/2015 1:18 PM, Måns Rullgård wrote: >>>>> 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 >>>>> >>>> [ 17.526173] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL >>>> [ 17.600124] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL >>>> [ 17.662978] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL >>> Could you post the entire kernel log? There might be important >>> information before the errors start. >>> >> >> >> =~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2015.12.18 15:01:48 =~=~=~=~=~=~=~=~=~=~=~= >> [ 0.000000] Using Canyonlands machine description >> [ 0.000000] Initializing cgroup subsys cpu >> [ 0.000000] Linux version 4.4.0-rc5-Sam460ex (root@julian-VirtualBox) (gcc version 4.8.2 (Ubuntu 4.8.2-16ubuntu3) ) #8 PREEMPT Fri Dec 18 13:36:34 AST 2015 >> [ 0.000000] Zone ranges: >> [ 0.000000] DMA [mem 0x0000000000000000-0x000000002fffffff] >> [ 0.000000] Normal empty >> [ 0.000000] HighMem [mem 0x0000000030000000-0x000000007fffffff] >> [ 0.000000] Movable zone start for each node >> [ 0.000000] Early memory node ranges >> [ 0.000000] node 0: [mem 0x0000000000000000-0x000000007fffffff] >> [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000007fffffff] >> [ 0.000000] MMU: Allocated 1088 bytes of context maps for 255 contexts >> [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 522752 >> [ 0.000000] Kernel command line: root=/dev/sda8 console=ttyS0,115200 console=tty0 dw_dmac_core.dyndbg dw_dmac.dyndbg I would suggest to use console=tty1 instead of console=tty0. > > [...] > >> [ 13.643415] systemd[1]: Mounted Configuration File System. >> [ 17.526173] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL >> [ 17.600124] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL >> [ 17.662978] sata-dwc 4bffd1000.sata: sata_dwc_qc_prep_by_tag: dma_dwc_xfer_setup returns NULL > > This log is weird. The sata_dwc_probe() function prints several things > (one using dev_notice()), for instance this: > > /* Read the ID and Version Registers */ > idr = in_le32(&hsdev->sata_dwc_regs->idr); > versionr = in_le32(&hsdev->sata_dwc_regs->versionr); > dev_notice(&ofdev->dev, "id %d, controller version %c.%c%c\n", > idr, ver[0], ver[1], ver[2]); > > The dw_dma_probe() function also prints a line: > > dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n", > pdata->nr_channels); > > These messages are nowhere to be seen in your log, nor are numerous > others that really must appear before before sata_dwc_qc_prep_by_tag() > can be called. > It would be better to add 'ignore_loglevel' to the cmdline as well. > I'd like to note that the driver works on my Sigma Designs based system > using a different DMA controller, so it's not completely broken. The > DMA driver could still be faulty, but that still doesn't explain the > missing kernel messages. > > -- > Måns Rullgård > -- > 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/ -- With Best Regards, Andy Shevchenko -- 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/