Re: [FFADO-devel] SVN 1122 comments/observations

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

Hi Pieter

>>> 1) With MOTU interfaces, the high-pitched sound on shutdown (and hense the
>>>    following startup) seems a lot more likely than revisions from a month or
>>>    so ago.  Has anything changed in the shutdown sequence which would affect
>>>    this.  In essence I suspect that not enough silence is being transmitted
>>>    to the device before the ffado systems shut down.  Do you have any
>>>    thoughts on this?
>> What happens if you increase the '200' to '2000' in 
>> StreamProcessor.cpp:1071?
> 
> Will test and advise.

I had a quick look at this.  The line referenced above deals with startup so
it had no effect on the shutdown process.  The problem really is at shutdown
as far as I can tell.  The MOTUs require a certain number of "silence"
packets to be sent at closedown or else we get this high-pitched thing
happening.  It therefore seems to me that upon jackd shutdown ffado isn't
allowing enough silence packets to be sent.  I had a brief look into this
last night but got lost in the state machine.  I'll make another attempt
over the weekend, but in the meantime is there a single define that controls
the amount of silence sent to a device during closedown?

> >>> 2) When running with verbose level 6 I used to get debug output during
> >>>    startup, with regular streaming system reports during the run.  Now I get
> >>>    nothing during startup, but during shutdown the shutdown debug messages
> >>>    appear as they always have.  It's almost as if the debug level only
> >>>    takes effect during shutdown.  jackd command line was something like
> >>>
> >>>      jackd -R -P60 -n 4 -p 1024 -d firewire -v 6
> >>>
> >> I have no idea what this is about. Sounds like some uninitialized value 
> >> problem.
> > 
> > It's odd that it would only start happening now.  I'll see if I can dig up
> > any more info on this.
> 
> I've seen more debug weirdness so I think I've probably checked in 
> something bad lately.

FYI the debug strangeness also affects the ffado dbus server.

Regards
  jonathan