[alsa-devel] TWL4030 Line In/Out Loopback issue

Almohanad Fayez alfayez at aol.com
Mon Aug 8 17:01:11 CEST 2011


 I can't seem to find a Left/Right Digital Loopback the mention of a loop I found is an FM Loop Enable.  The following is the dapm_widget enable output from my Gumstix Overo running the 2.6.38 Kernel.  Thanks for your help.

al fayez

root at usrp-e1xx:~# cat /sys/devices/platform/soc-audio/TWL4030/dapm_widget 
Headset Mic Bias: Off
Mic Bias 2: Off
Mic Bias 1: Off
micbias2 select: Off
micbias1 select: Off
Digimic1 Enable: Off
Digimic0 Enable: Off
ADC Physical Right: On
ADC Physical Left: On
Analog Right: On
Analog Left: On
ADC Virtual Right2: Off
ADC Virtual Left2: Off
ADC Virtual Right1: Off
ADC Virtual Left1: Off
HandsfreeR PGA: Off
HandsfreeL PGA: Off
CarkitR PGA: Off
CarkitR Mixer: Off
CarkitL PGA: Off
CarkitL Mixer: Off
HeadsetR PGA: On
HeadsetR Mixer: On
HeadsetL PGA: On
HeadsetL Mixer: On
PredriveR PGA: Off
PredriveR Mixer: Off
PredriveL PGA: Off
PredriveL Mixer: Off
Earpiece PGA: Off
Earpiece Mixer: Off
AIF Enable: On
APLL Enable: Off
Analog Voice Playback Mixer: Off
Analog L2 Playback Mixer: On
Analog R2 Playback Mixer: On
Analog L1 Playback Mixer: Off
Analog R1 Playback Mixer: Off
Digital Voice Playback Mixer: Off
Digital L2 Playback Mixer: On
Digital R2 Playback Mixer: On
Digital L1 Playback Mixer: Off
Digital R1 Playback Mixer: Off
FM Loop Enable: Off
DAC Voice: Off
DAC Left2: Off
DAC Right2: Off
DAC Left1: Off
DAC Right1: Off
PM State: On



-----Original Message-----
From: Péter Ujfalusi <peter.ujfalusi at ti.com>
To: alsa-devel <alsa-devel at alsa-project.org>
Cc: Almohanad Fayez <alfayez at aol.com>
Sent: Mon, Aug 8, 2011 4:56 am
Subject: Re: [alsa-devel] TWL4030 Line In/Out Loopback issue


On Monday 08 August 2011 02:27:45 Almohanad Fayez wrote:
>  I'verealized that there is a loopback dependency between the
> audioinput/output dependency with the 2.6.38 kernel running on a gumstix
> overo and also using the 2.6.35 kernel running on the Beaglenboard.

I can not recall seeing such an issue.

> You can replicate this issue by plugging some music into the Line injack and
> then fire up alsamixer.  Then you would need to modify theDAC2 Dig level,
> the one on the right no the left.  As you lower thevolume you'll hear your
> music input decreasing and as you increase itthe music level would
> increase.  If you lower it enough you can captureaudio from the input jack
> without hearing it out of your speaker butthe bad thing is that also
> controls your speaker output so if you tryto play some sound out of
> gumstix/beagleboard you won't be able to do because youneed to increase
> your DAC2 Dig level in alsamixer ... it's a catch22!!  I couldn't find any
> solutions readily.

Have you checked the state of the Left/Right Digital Loopback? Is it set to 0?

> I am running a console-only Angstrom image on both boards.  I've used the
> Beagleboard's line in/out capabilities with no issues using the 2.6.29
> kernel in the past so is there an update in the TWL4030 ALSA driver that I
> should take into account?  thanks

Could you post the content of the
file to see what's going on?



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