From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:27914 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199AbaBNAvp (ORCPT ); Thu, 13 Feb 2014 19:51:45 -0500 Message-ID: <52FD689D.5090109@flatmax.org> Date: Fri, 14 Feb 2014 11:51:41 +1100 From: Matt Flax MIME-Version: 1.0 To: Christian Gagneraud , linux-iio@vger.kernel.org Subject: Re: iio and jack - 1MHz sample rate success References: <52FB2477.9080108@flatmax.org> <52FD67A4.8050107@gna.org> In-Reply-To: <52FD67A4.8050107@gna.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 14/02/14 11:47, Christian Gagneraud wrote: > 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. > Thank you, The chips were AD7476A chips, so an SPI bus. There was hardware level and kernel level support from Lars-Peter Clausen and Alexandru Tofan. Matt > 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 > > -- > 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