From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com ([209.85.220.50]:55705 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440AbaBNArh (ORCPT ); Thu, 13 Feb 2014 19:47:37 -0500 Received: by mail-pa0-f50.google.com with SMTP id kp14so11495298pab.23 for ; Thu, 13 Feb 2014 16:47:36 -0800 (PST) Message-ID: <52FD67A4.8050107@gna.org> Date: Fri, 14 Feb 2014 13:47:32 +1300 From: Christian Gagneraud MIME-Version: 1.0 To: Matt Flax , linux-iio@vger.kernel.org Subject: Re: iio and jack - 1MHz sample rate success References: <52FB2477.9080108@flatmax.org> In-Reply-To: <52FB2477.9080108@flatmax.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 12/02/14 20:36, Matt Flax wrote: > > I have implemented the jack2 iio driver and have done a couple of tests. > > In a preliminary finding, waiting for more time to test and re-test, I > have had success. > I don't see any overruns reported (when setup properly), and I haven't > put a signal through the system to highlight any un-reported overruns. > Next week I will look into this more. Hi Matt, This is a very interesting usage of the linux-iio framework. Can you say a bit more about your analog front-end? Did you use an audio IC, or SPI/I2C ADC? If so which one. Thanks, Chris > > Firstly I would like to say that writing a driver for jack2 is a little > difficult because there is not much documentation ... at least I > couldn't find simple information. Some inline src doc would be good ... > mind you, I could have put more into my driver as well :) > > On the system with IIO devices I ran : > jackd -iio > > I then setup and ran netjack on both computers. > > On the other computer I used : > jack_capture -c 2 -p system:capture* > > ... wahlah ... it worked ! with an MTU of 1500. Thats 2 channels @ 1 MHz > > Everything reporting 1MHz sample rates and so on a so forth, no xruns > and the wav file looked like what I expected ... > > When I tried to record 4 channels @ 1 MHz, I had to increase the MTU to > 6000 to get rid of xruns on the ARM core. But still ... 4 channels @ > 1MHz over a network ... pretty good start ! > > I would like to integrate my both of my iio branchs into the jack1 and > jack2 repos, but for now I have forked the jack2 repo here : > https://github.com/flatmax/jack2/tree/iio > > I have some questions for other developers of jack2. > is it necessary to use : > JackDriver::CycleTakeBeginTime(); > and > JackDriver::CycleTakeEndTime(); > > ? > > thanks > Matt > p.s. Don't forget that these findings are very preliminary and things > need to be neatened up, debugged more and so on and so forth. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html