From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755145AbaIQIoy (ORCPT ); Wed, 17 Sep 2014 04:44:54 -0400 Received: from mail-bl2on0130.outbound.protection.outlook.com ([65.55.169.130]:15736 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751826AbaIQIot (ORCPT ); Wed, 17 Sep 2014 04:44:49 -0400 Date: Wed, 17 Sep 2014 16:51:08 +0800 From: Robin Gong To: Alexander Holler CC: , , , , , , , , , , , Subject: Re: [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl Message-ID: <20140917085106.GB6369@Robin-OptiPlex-780> References: <1410327012-31185-1-git-send-email-b38343@freescale.com> <5416D26A.4080707@ahsoftware.de> <20140916035204.GB20800@Robin-OptiPlex-780> <541805E3.6080003@ahsoftware.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <541805E3.6080003@ahsoftware.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:192.88.168.50;CTRY:US;IPV:CAL;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019020)(6009001)(24454002)(189002)(199003)(51704005)(93886004)(85306004)(46406003)(79102003)(74502003)(80022003)(50986999)(102836001)(33656002)(83506001)(76176999)(54356999)(33716001)(23726002)(110136001)(97736003)(99396002)(64706001)(50466002)(47776003)(104016003)(20776003)(87936001)(90102001)(74662003)(84676001)(26826002)(81342003)(46102003)(81542003)(77982003)(85852003)(83072002)(92726001)(92566001)(6806004)(31966008)(19580405001)(19580395003)(83322001)(44976005)(97756001)(21056001)(4396001)(106466001)(68736004)(76482002)(105606002)(107046002)(95666004)(32563001)(42262002);DIR:OUT;SFP:1102;SCL:1;SRVR:BLUPR03MB374;H:tx30smr01.am.freescale.net;FPR:;MLV:ovrnspm;PTR:InfoDomainNonexistent;MX:1;A:1;LANG:en; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;UriScan:; X-Forefront-PRVS: 0337AFFE9A Authentication-Results: spf=fail (sender IP is 192.88.168.50) smtp.mailfrom=yibin.gong@freescale.com; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 16, 2014 at 11:41:55AM +0200, Alexander Holler wrote: > Am 16.09.2014 05:52, schrieb Robin Gong: > >On Mon, Sep 15, 2014 at 01:50:02PM +0200, Alexander Holler wrote: > >>Am 10.09.2014 07:30, schrieb Robin Gong: > >>>There is one weird data in rxfifo after one full rx/tx transfer > >>>done sometimes. It looks a design issue and hard to workaround > >>>totally, so disable dma functhion here. And will re-enable it > >>>once the root cause found. > >> > >>Hmm, I experience problems with DMA too but on uart3. I'm using the same > >>workaround for the uart (I've just commented out the dma entries in the DT). > >>The problem manifests itself here such, that brcm_patchram_plus > >>hangs while uploading the firmware to a BCM4330 connected at uart3 > >>(reproducible). > >> > >>So maybe there is a bug in the DMA-engine which not only effects > >>SPI. Or both drivers contain the same error in handling DMA (maybe > >>through c&p). > >>But that's just specualtion from me, I haven't looked further into > >>that problem. > >> > >>Regards, > >> > >>Alexander Holler > >Thanks for your information share. But my issue should be caused by hardware, > >since everything is ok if it runs on other i.mx6 chip. Is your board also based > >on i.mx6 chip? If yes, hope you can raise your issue in freescale community or > >contact with Andy whose mail address added in CC list fugang.duan@freescale.cm. > >We have fix some bugs in UART DMA case. > > It's an i.mx6q (Wandboard quad c1) where I have this problem with > mainline and much older (but heavily patched freescale 3.10.x based) > kernels. A quick web-search suggests that this problem exists since > a long time (noticed mainly by people which try to use BT as this > seems to be the major use case for high speed serial communication). > > Regards, > > Alexander Holler Yes, we just have fixed the BT issue over high speed UART last month. Suggest you trying our patches based on v3.10.