Hi

On 7/11/20 6:33 AM, Dave Young wrote:
> Hi,
> 
> I'm trying to use g_audio on my Nokia N900 with mainline kernel. Seems
> it does not work.  No sound when I play from a laptop, and also see a
> lot of error like below:
> [ 4729.557647] omap-mcbsp 49022000.mcbsp: TX Buffer Overflow!
> ...
> 
Head 0dc589da873b ("Merge tag 'iommu-fixes-v5.8-rc5' of
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu") records and
plays fine here (arecord -f dat |aplay), although I see some of those
errors but don't hear any glitches etc.

Peter, does above indicate a serious issue or is it perhaps a false
alarm on OMAP3 (no audible glitches)?

I believe you don't have some mixer knob on, N900 audio path is somewhat
complex and needs bunch of mixer switches and volumes to be set. I
attached my N900 mixer scripts for you to try.

Set first everything off:
./aic34_scripts/shutdown.sh

Then enable internal digital microphone and speakers:
./aic34_scripts/dmic.sh
./aic34_scripts/speakers.sh

Hopefully these help you get going :-)

-- 
Jarkko