[LAU] Phonic Helix Board 24 on Fedora

[Mark Knecht]

On Sun, Feb 15, 2009 at 2:36 AM, Pieter Palmers <pieterp at joow.be> wrote:
> Mark Knecht wrote:
>>
>> On Sat, Feb 14, 2009 at 8:14 AM, Pieter Palmers <pieterp at joow.be> wrote:
>>>
>>> Jonathan Gazeley wrote:
>>>>
>>>> Hi all,
>>>>
>>>> I'm trying to set up my Phonic Helix Board 24 on Fedora 10. I've added
>>>> the CCRMA repository but I'm *not* running a CCMRA kernel. I have just
>>>> used this repository to install ffado and jack.
>>>>
>>>> [jonathan at poseidon ~]$ uname -r
>>>> 2.6.27.12-170.2.5.fc10.i686.PAE
>>>>
>>>> [jonathan at poseidon ~]$ rpm -q ffado
>>>> ffado-2.0-0.6.rc1.fc10.ccrma.i386
>>>>
>>>> Starting jack gives the output below. Running as root gives exactly the
>>>> same output. I've made sure that all users have read/write permissions on
>>>> the firewire port (chmod a+rw /dev/fw*)
>>>>
>>>> I'm a fairly experienced Linux user but I know very little about audio
>>>> on Linux. Can anyone shed any light on this? I had the same Phonic device
>>>> working on Fedora 8 some time ago but that computer is now a distant
>>>> memory...
>>>>
>>>> Any help will be gratefully accepted!
>>>> Thanks,
>>>> Jonathan
>>>>
>>>>
>>>> [jonathan at poseidon ~]$ jackd -d firewire
>>>
>>> Run jackd in realtime mode.
>>>
>>> Pieter
>>
>> Is his kernel even a real-time kernel? I don't get that from the uname
>> output...
>
> What I mean is:
>
> jackd -R -d firewire
>
> That doesn't require a RT kernel. Don't expect FFADO to work properly when
> jack doesn't run in realtime mode (-R). The same applies for ALSA or other
> backends btw, but FFADO is particularly sensitive.
>
> Greets,
>
> Pieter
>

Right, and OP should not expect zero xruns if he isn't using a real-time kernel.

There is a real rash lately of users trying to do real-time work
without a real-time kernel. For some reason they put Jack support in
MythTV and I've seen a couple of people there in the last few weeks
that weren't even aware that there was a real-time kernel, much less
actually using it, and they were complaining of xruns.

- Mark