[ALSA - driver 0001731]: Fixed chip configuration for 5.1 in ALC850 code

bugtrack
2006-01-11T17:38:33Z

Last Modified: 01-11-2006 18:38 CET
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Summary: Fixed chip configuration for 5.1 in ALC850 code
Description:
Frustrated by the fact that the 5.1 DVD I just bought had no voices (since
they were on the center channel) I started to dig into it. The details are
in the "steps to reproduce".

Attached is a (very) small patch that fixed it completely on my system
(both the mixer and the channel mix-up). My guess is that the chip was
misconfigured by lack of a bit in the MX76 register. (2 instead of 5 for
bits 6:4)
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C-MoH - 01-11-06 11:58
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I only tested the patch superficially with speaker-test and the DVD which
brought me to this.

What I did and worked fine:
speaker-test -Dsurround51 -c6
speaker-test -Dsurround40 -c4
speaker-test -c2

For the 5.1 DVD everything was now fine (mixer, sound quality, voice
etc.):
mplayer -ao alsa -channels 6 dvd://

Also with alsamixer the mixer channels (center and lfe) now do have effect
over the volume/muting of sound. The behavior of switches is no longer
erratical (i.e. the IEC958/Mix/Mono Mix/Video/DuplicateFront had a weird
interaction, which now seemed to have a more normal aspect - in fact I
never thought much of it, but I remarked it now).

All this made me think it's all right. If you take the time to look at the
patch and at the ALC850 specs from Realtek you'll see that... well,
there's not much to verify it's correctness.

If there's more to do I'll do it and post it here. Remember I'm not a dev
here, thus not accustomed to your procedures (I did assume big projects
like this do have regression tests). If you want me to do more tests etc.
send me the instructions.

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rlrevell - 01-11-06 18:38
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Ah, OK, I missed the part where you said the patch was based on the ALC850
datasheet.

Maintainers, this patch should be applied for the 1.0.11 release.

Issue History
Date Modified Username Field Change
======================================================================
01-11-06 01:17 C-MoH New Issue
01-11-06 01:17 C-MoH File Added: cipi.patch
01-11-06 01:21 C-MoH Issue Monitored: C-MoH
01-11-06 01:22 C-MoH Note Added: 0007553
01-11-06 01:33 rlrevell Note Added: 0007554
01-11-06 01:37 C-MoH Note Added: 0007555
01-11-06 01:40 rlrevell Note Added: 0007556
01-11-06 11:54 C-MoH Note Added: 0007562
01-11-06 11:58 C-MoH Note Edited: 0007562
01-11-06 18:38 rlrevell Note Added: 0007565