On Thu, Apr 23, 2009 at 02:52:24PM +0300, Peter Ujfalusi wrote:
I have a theory, which needs to be checked for the startup switch in OMAP: I think what is happening, that the McBSP module got enabled earlier then the DMA is started. This leads to and underrun situation in McBSP (no data in the buffer), so McBSP will transmit _something_ when the start condition for the I2S is met. When the DMA starting to push data to McBSP, than valid data will be shifted out. McBSP is shifting word by word manner. So if the first word transmit need to be done, when the buffer is empty, it starts to shift the word, than the data arrives from the DMA, the next word will be valid data -> you will have a nice channel switch.
Is this makes sense?
Sounds entirely plausible to me.