[alsa-devel] [2.6.30-rc2][PATCH 1/2] ASoC: OMAP: Fix DSP_B format in OMAP McBSP DAI driver
Jarkko Nikula
jarkko.nikula at nokia.com
Fri Apr 17 08:59:23 CEST 2009
On Thu, 16 Apr 2009 23:35:20 +0200
ext Troy Kisky <troy.kisky at boundarydevices.com> wrote:
> Arun KS wrote:
> > But when I2S is used there is no audio on Right channel(left channel
> > is working fine).
> > Thinks something is missing on tlv320aic23 driver.
> >
> This sounds like the same problem Davinci has. From a comment in
> davinci-i2s.c
>
> case SND_SOC_DAIFMT_I2S:
> /* Davinci doesn't support TRUE I2S, but some codecs will have
> * the left and right channels contiguous. This allows
> * dsp_a mode to be used with an inverted normal frame clk.
> * If your codec is master and does not have contiguous
> * channels, then you will have sound on only one channel.
> * Try using a different mode, or codec as slave.
> *
> * The TLV320AIC33 is an example of a codec where this works.
> * It has a variable bit clock frequency allowing it to have
> * valid data on every bit clock.
> *
> * The TLV320AIC23 is an example of a codec where this does
> not
> * work. It has a fixed bit clock frequency with progressively
> * more empty bit clock slots between channels as the sample
> * rate is lowered.
> */
Interesting codec. Arun, how is the right channel working with I2S if
you try to run with higher rate? E.g. aplay -r [48000 |
96000] /dev/urandom
The I2S mode setup in tlv320aic23_set_dai_fmt looks correct.
Jarkko
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