[LAU] AVB on Linux

[Fernando Lopez-Lezcano]

On 7/13/21 8:20 AM, Brandon Hale wrote:
> Thanks so much for these links Fernando. I've played with the OpenAvnu 
> repo about 2 years ago, but I couldn't get it working as I didn't know 
> what I was doing. I'll try compiling it with the standard Linux network 
> stack and see how far I get.
> 
> I don't currently have a motu avb interface, but I do have access to an 
> RME Digiface AVB <https://www.rme-usa.com/digiface-avb.html>. I'll look 
> through those repositories, but I figure there's not much I can do with 
> that interface on Linux as of yet. :(
> 
> What interface do you use to get the 64 channels over usb?

There are several, at home I currently have an 8M and a 16A and I am 
driving them through a patched kernel with the drumfix's driver (caveat: 
the driver does NOT work with an RT patched kernel - something to do 
with the number of interrupts generated and context switches - but it 
works fine with a full preemption kernel with threadirqs disabled), 
details in this thread:

https://linuxmusicians.com/viewtopic.php?f=6&t=18046&sid=5021bc427a7f0abd6b7a24c8aaef15d7&start=630

For a couple of our speaker arrays I have again used 16A and 8M mainly 
as gateways into a larger array of Motus[*], but the 24ai and 24ao also 
work. For these I am still running old firmware and the regular usb 
driver in linux (newer Motu interfaces cannot be downgraded to old 
enough firmware for the class compliant driver to work).

-- Fernando

[*] https://ccrma.stanford.edu/~nando/publications/stage_grail_2019.pdf


> On 7/13/21 2:17 AM, Fernando Lopez-Lezcano wrote:
>> On 7/12/21 3:47 PM, Brandon Hale wrote:
>>> Hello all,
>>>
>>> Are there any of you here who are using AVB on Linux, especially with 
>>> a standard Ethernet port? What software or hardware are you using to 
>>> do this on your Linux machines? I am interested in playing with it 
>>> and have some AVB speakers to mess with, but I'm not sure if it is 
>>> even possible yet, especially with a standard laptop Ethernet port.
>>>
>>> Tell me about your Linux AVB success stories!
>>
>> None yet... :-(
>>
>> Regarding the use of i210 network interfaces, a while back I found this:
>> https://github.com/AVnu/OpenAvnu/issues/601
>>
>> ----
>> At the top-level of the OpenAvnu checkout, run this make command:
>>
>> $ PLATFORM_TOOLCHAIN=generic make avtp_pipeline
>>
>> That will prevent it from linking to the i210 library and instead use 
>> the standard Linux network stack. The packet launch times and 
>> presentation timestamps will be
>>  far less even and I'm working on ways to lessen those problems, but 
>> you should be able to get a talker and listener built from the 
>> avtp_pipeline code to work toge
>> ther with some tweaking of the avtp_pipeline INI files. Be sure to 
>> read through the documentation that comes with the avtp_pipeline code.
>> ----
>>
>> But never had a chance to test it and see if it really works...
>>
>> Then there is this software:
>> https://github.com/Drumfix/avb4linux.git
>>
>> This is just 8 ports i/o on linux for motu avb cards, but it needs an 
>> i210 NIC (by the same guy that posted an experimental driver for 
>> proprietary usb mode on Motu's - in the LinuxMusicians forum - so you 
>> can get 64 channel i/o over usb with the newest firmware - I am using 
>> it and it works quite nicely).
>>
>> -- Fernando