Re: [FFADO-user] Firewire Audio Setting RME FF400 into Ubuntu 20.10

[Jonathan W. <jw...@ju...>]

Hi Riccardo

Thanks for providing the requested information.

On Tue, Nov 24, 2020 at 01:50:19PM +0000, Riccardo Wanke wrote:
> I had already added my user to audio's group.

Great - it is good to have this confirmed.

> Your wrote that, in order to use the FF400 I can either use ALSA and
> FFADO, I would probably would use FFADO (in any case I keep in mind the
> other solution, thanx!).

To be clear, this is referring to the task of getting audio into and out of
the audio interface.  Regardless of which audio option you choose,
ffado-mixer can be used to control the device settings.  For now we'll
assume that the goal at this point is to use FFADO with jackd to transport
audio to and from the device.

> I checked /etc/modprobe.d/blacklist.conf and there
> is no trace of firewire modules

Good, that is what I would expect.

> and in /etc/modprobe.d/blacklist-firewire.conf everything is disabled:
> 
> # Select the legacy firewire stack over the new CONFIG_FIREWIRE one.
> #blacklist ohci1394
> #blacklist sbp2
> #blacklist dv1394
> #blacklist raw1394
> #blacklist video1394
> #blacklist firewire-ohci
> #blacklist firewire-sbp2

This is also good.  There is nothing to be gained by disabling the entire
kernel firewire stack, especially if you want to use firewire. :-)

If you have the ALSA "fireface" module configured in your kernel and you
wish to use FFADO for audio streaming, you will need to blacklist
snd-fireface in /etc/modprobe.d/blacklist.conf:

  blacklist snd-fireface

Give the rest of the output (discussed below) this is not currently an
issue.  It is something to keep in mind for later though.

> Now, here the complete output of the following commands (when RME is
> connected): lsusb

> $ lsusb
> :
> Bus 001 Device 005: ID 05ac:1657 Apple, Inc. Thunderbolt 3 (USB-C) to
> Thunderbolt 2 Adapter

This shows that your system can see the Thunderbolt-3 to Thunderbolt-2
adapter.

There is no mention of the Thunderbolt-2 to firewire adapter in either lsusb
or lspci.  I would ordinarily expect to see it in lspci since Thunderbolt-2
is, as I understand it, an extension of the PCIe bus.  However, maybe it's
structured as a transparent bridge and not visible.  Regardless of that, the
Thunderbolt-2 to firewire adapter ought to be visible in lspci, as could be
seen in Michael in his post to ffado-user on 15 Jan 2017 (Subject: Re:
[FFADO-user] ffado, thunderbolt and a realistic expectation).

The inability to see the firewire adapter is reflected in the ffado-diag
output: there are no /dev/fw* device nodes reported.  This shows that the
firewire adapter itself cannot be seen by the computer, let along the audio
interface attached to it.  Obviously without an ability to see the firewire
adapter, anything connected to the firewire bus cannot be detected by the
computer.

On this basis the problem you are experiencing is a failure of your computer
too see the firewire adapter through the Thunderbolt-3 to Thunderbolt-2
adapter.  The Thunderbolt-3 to Thunderbolt-2 adapter is seen though, which
is a good start.  Suffice to say that the problem lies outside of FFADO:
FFADO cannot utilise a device which the computer cannot see.

I am not sure what to suggest at present - I don't know why the firewire
adapter would not be detected on the Thunderbolt-2 bus.  We have had reports
in the past that Thunderbolt-2 to firewire adapters have worked with FFADO
(refer to the ffado-user thread mentioned earlier for example).  However,
I'm not sure that anyone has successfully used a chain like you have
starting with Thunderbolt-3 (or USB-C).

Do you have any other Thunderbolt-2 devices?  Are they detected by your
computer through the Thunderbolt-3 to Thunderbolt-2 adapter?

Do you see any interesting messages in the output from the "dmesg" command
after you've connected the adapters and audio interface?

Regards
  jonathan