[alsa-devel] [PATCH] pcm: route: Don't handle no matching chmap as a serious error

[Takashi Iwai]

At Tue, 18 Mar 2014 23:13:02 +0100,
David Henningsson wrote:
> 
> On 03/18/2014 05:34 PM, Takashi Iwai wrote:
> > At Tue, 18 Mar 2014 17:19:29 +0100,
> > David Henningsson wrote:
> >>
> >> On 03/18/2014 03:27 PM, Takashi Iwai wrote:
> >>> When find_matching_chmap() returns an error for the non-matching
> >>> chmap, the caller, snd_pcm_route_open(), also returns an error
> >>> although it shouldn't be handled as the fatal error.  This results in
> >>> the probe error with PulseAudio and it gives no real output in the
> >>> end.
> >>
> >> Hmm, could you give a more specific example? In case the driver does not
> >> support channel maps at all, that case is handled in the beginning of
> >> the function.
> > 
> > Well, the problem is that PulseAudio doesn't work at all with the
> > current alsa-lib git prior to the commit in some cases.  That is, the
> > commit brought some incompatibility.
> 
> Hmm, then the error should be somewhere in determine_chmap instead.
> tt_chmap should be NULL (i e, find_matching_chmap is never called) for
> using the standard number syntax instead of the new chmap syntax.
> 
> What about the patch attached instead (untested) ?
> 
> >> So this only happens if the driver supports channel maps, but only
> >> non-compatible with the requested map. In which case I believe it's
> >> correct that the probing should fail...?
> > 
> > Could you check whether PA 5.0 works as is with alsa-lib git (before
> > the last fix)?  It could be seen on some desktop machines.
> 
> Let me know if the attached patch works for you. In case it does not I
> will do this testing later.

It seems working, but it revealed another bug, too.  I fixed it in git
tree, and reverted my last patch along with it.


thanks,

Takashi