Hi All,

I'm trying to get my audio to work nicely on the 9263 evaluation kit.
I am running kernel version 2.6.30 from org.openembedded.dev and trying to interface to the alsa libraries. Running aplay and arecord individually works nicely and I can record / playback OK so long as I give it the right parameters:

However, I need to have full-duplex audio (which the audio codec part should support) which I'm testing by piping the record to the playback:

In this case I just get silence.
I've also tried using the code from here:
http://www.linuxjournal.com/article/6735
and piped listing 4 to listing 3 as suggested, but no dice.
Does anyone know where I might be going wrong? I figure it must be one (or more) of
1) I'm doing something silly. But both tests work OK on my desktop linux, so it doesn't seem like a totally stupid test.
2) The port of the alsa drivers to this architecture don't like full-duplex audio for some reason.
3) The AC97 driver code doesn't like full-duplex audio for some reason.
Anyone got any ideas on this? There was a similar thread back in August, but it didn't seem to reach a resolution...

Many Thanks,
John Martindale, Practical Control Ltd.

Hi all,

Just as an update, I got a USB audio device off Amazon, enabled USB audio support in the kernel and reflashed the board...

Using code examples 3 and 4 from http://www.linuxjournal.com/article/6735 I can successfully loop the capture stream back into the playback stream on the USB audio device. If I try the same code examples using the onboard sound device I don't get any loopback audio, though saving and playing audio to / from a file both work fine individually.
So... it seems like the AC97 driver doesn't like full-duplex audio. Unfortunately I don't have the time (expertise?!) to look into this any further - just thought I'd put the info out there in case anyone else is trying to do the same thing.
I'd love to hear if anyone else has experience with this and I'm just doing something daft!

Cheers, John
Practical Control

Kernel 2.6.30. On-board test:16KHz, 2-channel. USB audio: 48KHz, capture 1ch doubled up in code, playback 2ch.

Hi.

Linux ac97 driver uses PDC and channel A of the Atmel ac97. It can't use channel B with PDC, because of architecture of at91sam9263. What's why it can't be a full duplex system without using both channel A and B. If somebody rewrites driver to use both channel A and B without PDC or use PDC only for playback and capture without PDC, so it is possible to make a full duplex driver for this chip in Linux. It's only my opinion. I want to use ac97 as a full duplex system too. So I'm a little disappointed with that.

Hello.

What is the solution that you have chosen to solve this problem?.
Anyone has get AC97 driver supporting full duplex in AT91SAM9263?.

I´m in the same, and I´m not sure what to do.......

thanks for your help

regards