Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752187AbbLRXQq (ORCPT ); Fri, 18 Dec 2015 18:16:46 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:49107 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751592AbbLRXQo convert rfc822-to-8bit (ORCPT ); Fri, 18 Dec 2015 18:16:44 -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> <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: Fri, 18 Dec 2015 23:16:41 +0000 In-Reply-To: <56748D85.4060108@candw.ms> (Julian Margetson's message of "Fri, 18 Dec 2015 18:49:41 -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 Content-Length: 4596 Lines: 93 Julian Margetson writes: > On 12/18/2015 6:33 PM, M?ns Rullg?rd wrote: >> Julian Margetson writes: >> >>> On 12/18/2015 1:18 PM, M?ns Rullg?rd wrote: >>>> Julian Margetson writes: >>>> >>>>> On 12/18/2015 8:49 AM, M?ns Rullg?rd 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 [...] > [ 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. 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. -- M?ns Rullg?rd -- 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/