Re: [Jack-Devel] incompatible version of ffado error message

On Tue, 2012-05-01 at 09:38 +0930, Jonathan Woithe wrote:
> On Mon, Apr 30, 2012 at 03:35:54PM +0200, Adrian Knoth wrote:
> > On Mon, Apr 30, 2012 at 11:26:32PM +1000, Allan Klinbail wrote:
> > > I've been using jack with ffado as the driver for a few years now.
> > > Today, after upgrading ffado to the latest svn , (then tested working).
> > > I then upgraded to the latest jack svn version. Following this I started
> > > receiving the following incompatible error message. 
> > 
> > You were doing it in the wrong order.
> > 
> > FFADO detects the jackd version at compile time. If it's a new jackd
> > version supporting the new API, it switches to the new API.
> 
> Similarly, if there is no jackd installed at compile time ffado assumes that
> the jackd which will ultimately be available will support the new API.
> 
> So in Allan's case, he compiled a new FFADO against an old jack, which
> resulted in a FFADO which uses the old API.  The old jack was happy with
> this and everything worked.
> 

I tried this in a few different ways in the end .. Same result. 



> > You've just told FFADO to adjust itself to an old jackd version.
> > Simply compile FFADO again.
> 
> Yep, that should work.
> 
> However, from a development point of view I'm a little surprised that the
> latest jackd didn't simply accept FFADO as it was.  The relevant line in
> current jack1 is drivers/firewire/ffado_driver.c, line 786 and following.
> 
>   if(ffado_get_api_version() < FIREWIRE_REQUIRED_FFADO_API_VERSION) {
>     printError("Incompatible libffado version! ...
>   }
> 
> The same conditional is used in jack2, so the following analysis applies
> equally to that.
> 
> In Allen's case, ffado_get_api_version() would return 8 (the old version).
> FIREWIRE_REQUIRED_FFADO_API_VERSION is defined as 8, so this conditional
> *should* have failed and the "Incompatible libffado version" message should
> never have been displayed.
> 
> Oh hang on: Allan, you said "the latest jack svn version".  Did you
> literally use jack's subversion repository?  That is no longer carrying the
> latest jackd source as far as I know: if you want the latest jackd you need
> to get it using git.  This is described at
> 
>   http://jackaudio.org/download


Okay, jackd was built from the "live" ebuild in the gentoo pro-audio
repository, I would have to look at the ebuild for that to determine if
it was taking the older svn version or the git version. 




> 
> Look for the "JACK Source Code Repository" section about half-way down.
> 
> I don't know the state of jack's ffado driver in the old svn repository, but
> the use of the older jack code (which could be in an unstable intermediate
> state with respect to ffado driver updates) may explain the symptoms
> described.
> 
> Regards
>   jonathan

1335911921.5512_0.ltw:2,a <1335911348.9393.1.camel at srv3 dot little-wolf dot local>