[ALSA - driver 0002159]: ac3 passthrough not working on recent versions

bugtrack
2006-06-17T08:21:07Z

Last Modified: 06-17-2006 10:21 CEST
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Summary: ac3 passthrough not working on recent versions
Description:
Using the following AC3 passthrough with mplayer works:
Linux 2.4.31
alsa-driver 1.0.8-7 (debian stable packaged)

Using Linux 2.6.15 (both with alsa-driver 1.10rc3 that ships with the
kernel and
alsa-driver 1.0.11) it doesn't work. The reciever just says "unlock" and
stays quiet.

The only change is booting with different kernels, no other config or
hardware is touched, so this must be a driver regression.

The card is YMF-754 based, connected with coax spdif to my HK reciever.

If you need more info, just tell me and I'll dig it up.
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nikke - 06-17-06 01:17
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I tried to do a quick revert of just that patch from 1.0.11, but there was
too many conflicts... However, I noticed that the
rear-channel-swapping-thingie shows up in the same function that this
patch modifies the most. And since AC3 passthrough works in 1.0.9 this
suggests that the patch really breaks things that the
rear-channel-swap-patch tries to fix...

Mimosius: Can you make a patch between stock 1.0.11 and your
1.0.11-with-working-ac3 so I can test too, and other people really can see
that it's the mentioned patch that breaks things?

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Raymond - 06-17-06 10:21
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Which application change those undocumented registers of STAC9708 ?

0:68 = 0000
0:6a = 0000
0:6c = 0000
-0:6e = 0004
+0:6e = 0008
0:70 = 0000
-0:72 = 8000
+0:72 = ffef
0:74 = 0380
0:76 = abba
0:78 = 9381

Are all channels correct when you run speaker-test -c 4 -t wav ?