From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bo Shen Subject: Re: [RFC PATCH 01/13] misc: atmel_ssc: add device tree DMA support Date: Thu, 4 Jul 2013 09:15:00 +0800 Message-ID: <51D4CC94.3020908@atmel.com> References: <1372667978-4718-1-git-send-email-richard.genoud@gmail.com> <1372667978-4718-2-git-send-email-richard.genoud@gmail.com> <51D24299.9050209@atmel.com> <51D29927.80900@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Richard Genoud Cc: devicetree-discuss@lists.ozlabs.org, Nicolas Ferre , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, =?UTF-8?B?VXdlIEtsZWluZS1Lw7ZuaWc=?= List-Id: devicetree@vger.kernel.org Hi Richard, On 7/3/2013 23:51, Richard Genoud wrote: >> >but there's a violent hang (kernel stops, no trace) when I try the record : >> >arecord -v -V stereo -Dplug:default -f cd -t wav -c 2 /tmp/toto.wav >> >last thing I see is : >> >dma dma0chan3: atc_control (3) I don't meet this issue. Playback and recording works well on my side on at91sam9g35ek board. >> >I'll try to trace that. > I think it's DMA related. > the last thing done by the kernel is: > i2c i2c-0: i2c_outb: 0x34 A > i2c i2c-0: i2c_outb: 0x0c A > i2c i2c-0: i2c_outb: 0x5a A > meaning: enable power on, LINE IN, ADC, OSC, on the WM8731 > so, after that, data is comming from the codec to the SSC and then is > handled by the DMA. > there must be something nasty on the DMA bus to hang everything like that... Will you try i2c without DMA support to test this issue? > Richard. Best Regards, Bo Shen