Hi, On 14/07/2020 21.03, Jarkko Nikula wrote: > 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 need to dig out my n900 or beagleXM, but it is hard to believe it is not a result of a glitch. The DMA is triggered by McBSP and it should write exactly what McBSP expects to be receiving. I can not recall any changes in the past years which would have introduced regressions in McBSP or the sDMA driver. > 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. This could be the reason for the silence, I have asoundrc files somewhere to restore a 'good' mixer config. > 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 :-) > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki