[alsa-devel] snd-soc-pxa-ssp I2C/FIFO issues

pHilipp Zabel philipp.zabel at gmail.com
Mon Mar 9 15:47:35 CET 2009


I'm not sure how to handle this correctly.

Magician needs stereo S16_LE input data from alsa, DAIFMT_DSP_A on the
wire with a frame size of 16 bit (one frame for each channel) and thus
2-byte DMA transfers to the FIFO (currently called 'mono' DMA params).
Zylonite's current code uses 32 bit frame size and 4-byte DMA
transfers to emulate I2S (S16_LE,stereo). Network mode seems to work,
so it could be changed to use two 16 bit slots instead with 2-byte DMA
transfers (which would make Magician happy). But...
Daniel's board needs very strange settings because network mode
doesn't work, so I guess he can't use 2-byte DMA transfers. Is that

If we can't find a way to have all machines use the mono DMA params,
there has to be some kind of interface to set the width of the data in
the FIFO independently from the Alsa format. How should that interface
look like?


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