[alsa-devel] [PATCH 1/2] ASoC: omap-mcbsp: Use DMA packet mode for non mono streams on OMAP3+

Jarkko Nikula jarkko.nikula at bitmer.com
Fri Mar 16 08:00:12 CET 2012

On 03/15/2012 12:37 PM, Peter Ujfalusi wrote:
> Take the DMA packet mode into use when the McBSP is configured in element
> dma_op_mode if the stream is not mono.
> In this way we transfer one sample from/to McBSP FIFO upon DMA request.
> This change only affects OMAP3+ versions, where the McBSP ports have FIFO.
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
> ---
>  sound/soc/omap/omap-mcbsp.c |   30 +++++++++++++++++-------------
>  1 files changed, 17 insertions(+), 13 deletions(-)
Out of curiosity, I guess this will decrease a memory bus or DMA
controller load a bit. Can you see any difference with the SW tools
(top, etc) under some system load or do you need some on-chip
observability to be able to measure effect of this transfer pattern change?

Just willing to learn here :-)


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