[PATCH] pmac: sound support for latest laptops
benh at kernel.crashing.org
Tue Apr 12 10:04:50 EST 2005
On Mon, 2005-04-11 at 17:07 +0200, Johannes Berg wrote:
> >This patch hacks the current Alsa snd-powermac driver to add support for
> >recent machine models with the tas3004 chip, that is basically new
> >laptop models. The Mac Mini is _NOT_ yet supported by this patch (soon
> >soon ...). The G5s (iMac or Desktop) will need the rewritten sound
> >driver on which I'm working on (I _might_ get a hack for analog only on
> >some G5s on the current driver, but no promise).
> That's cool. I do have one slight problem with it though: When I turn
> down the Master mixer and up PCM it sounds badly overmodulated. I can
> keep PCM at about 75% and turn up master, and all is fine. Would it make
> sense to limit the PCM mixer to about 75% of its current limits, or how
> does that actually work in the hardware?
Well, the driver will let you do the setting you want, even if it's
wrong :) You should indeed keep PCM at about 75% and use the master.
There is also an issue with bad quality speakers used by Apple. OS X has
a built-in software DSP that does equalisation & filtering in the kernel
driver, and they have specific settings for it for various machine model
speakers. Obviously, we don't have such thing.
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