[ltp] cs4624 sound

[Chris Schumann]

> Date: Wed, 06 Jun 2007 23:31:25 +0100
> From: Simon Williams <simon@systemparadox.co.uk>

> Chris Schumann wrote:
>> The cs46xx ALSA driver has had a bug for four years. There's no sound
>> after suspend and resume, at least with the cs4624 chip that is in the
>> 600X, T20, T21, T22, A20m, A20p, A21m, A21p, A22m, and A22p.

> I had a 600 (not E or X) (which I'm sure had a very similar card, if not
>  the same one), and a T20. Both worked perfectly before and after
> suspend, with no messing required. This was with kernel 2.6.8.1 on the
> T20 before I upgraded.

I suppose I could try an old distribution... nothing to lose but some
time, and the risk of learning something.

> Like I said, I never had any problems with suspend until my T23, but if
> you do maybe the mixers will help.

I'll give that a try. Sound apps hang after a resume, so they don't seem
like they are muted, but maybe the muting/unmuting might fix things
anyway.

> When you say the driver has a bug, is this inside knowledge or are you
> just going by it not working with your setup?

Alsa #305. https://bugtrack.alsa-project.org/alsa-bug/view.php?id=305

> Hope this helps. Let me know if there is anything else I can do. If you
> really need I might be able to borrow my old T20 for a few hours (though
>  it won't be that easy).
> Simon

Well, if you could get that T20 working with a modern distribution using
the Alsa cs46xx driver, you'd make me very happy!

I have the driver source installed and building, but there's something
like 4000 lines of code. I can find the suspend and resume functions, but
I don't know what they are supposed to do without the datasheet for the
chip, and that is apparently non-existant. I don't think libraries hang on
to chip maker data books.

Chris