[alsa-devel] [PATCH V2] ASoC - Add support for upto 16 channels on OMAP MCBSP

Peter Ujfalusi peter.ujfalusi at nokia.com
Mon Nov 9 07:57:22 CET 2009

On Sunday 08 November 2009 22:27:01 ext Liam Girdwood wrote:
> Any chance we could have your Ack before applying.

Well, I have tried it on a system, where the McBSP is slave (codec provides the 
bit and FS clock) with the following result:

aplay -Dplughw:0 /usr/share/sounds/alsa/Front_Center.wav -q
omap_mcbsp_dai_hw_params: not enough bandwidth for desired rate and channels
asoc: interface omap-mcbsp-dai-0 hw params failed
aplay: set_params:1022: Unable to install hw params:

So this patch definitely breaks McBSP slave mode.
In case when McBSP is slave, the SRG is not in use, and there is no point of 
passing some bogus information in order to pass the test in 
omap_mcbsp_dai_hw_params introduced by this patch.

I think if I set the mcbsp_data->in_freq to be:
params_rate(params) * sample_bits * channels, and configure the mcbsp_data-
>clk_div to be 1, might work in this case.

But after this patch the beagle board and boards which has the McBSP as slave 
will stop working.

I'm afraid, I can not give my Ack for this :(

> Thanks
> Liam


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