[alsa-devel] pxassp dma pointer not moving

Liam Girdwood lrg at slimlogic.co.uk
Sun Feb 22 23:07:57 CET 2009


On Sun, 2009-02-22 at 22:47 +0100, Daniel Mack wrote:
> Hi,
> 
> I'm currently implementing support for a board based on a PXA300 with an
> I2S codec (CS4270) next to it. Things do work in general, including the
> setup of the SSP engine and clocks, and when using the OSS compat layer,
> I can see data on the bus. With the native ALSA API, however, the DMA
> pointer does not move forward but is stuck at position 8. ALSA's core
> calls pxa2xx_pcm_pointer() a couple of times and eventually gives up on
> it. Unfortunately, I don't have a Zylonite board for cross-check; could
> anyone verify that things are not currently broken in a general way?
> 
> My code base is up-to-date to sound-2.6.git/for-2.6.30.

Can't test on my zylonite atm, but static DMA pointers usually mean data
is not being clocked out of the SSP FIFO. Can you check you are
supplying a BCLK and LRC to the SSP port (if codec is BCLK/LRC master)
or have enabled the PXA SSP master mode (if codec slave).

Liam



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