On 11/04/2015 07:11 PM, Nicolin Chen wrote: > On Wed, Nov 04, 2015 at 06:52:12PM +0100, Roberto Fichera wrote: > >>> I notice your DMA buffer length is very short, which would require >>> very frequency interrupts to service, right? Can you increase your >>> DMA buffer length by increasing the period size? Maybe that would >>> help reduce the likelyhood of a failure. >> Not sure if this can help! SSI TDM is set to 32 slots but only 2 are masked. So every frame only >> 2 slots are pushed/pulled from the FIFOs. maxburst is set to pull a block of 8 elements from the >> FIFOs, DMA cyclic call it period. So the full DMA buffer is filled in buffer size / period DMA iterations. > A smaller period size may course DMA buffer over/underrun -- ALSA > over/underrun even though it seems that you didn't report any. > > And apparently SDMA would get more interrupt/callbacks. I would > suggest a larger period size and buffer size although I cannot > tie your problem with the size. But you may try. > Following your suggestion, I've increased the buffer size to 2K and set the period to fifo_length - 2 (13), with that I'm now running substantially smooth except 3 EVTERR on RX DMA over 4 million of interrupts. Thanks Nicolin! I'm quite happy now! _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
