On Mon, Jun 22, 2015 at 11:14:42AM +0900, Krzysztof Kozłowski wrote: > 2015-06-15 23:00 GMT+09:00 Krzysztof Kozlowski <k.kozlowski.k@xxxxxxxxx>: > > When pl330 driver was used during sound playback, after some time or > > after a number of plays the sound became choppy or totally noisy. For > > example on Odroid XU3 board the first four executions of aplay with > > small WAVE worked fine, but fifth was unrecognizable with errors: > > $ aplay /usr/share/sounds/alsa/Front_Right.wava > > underrun!!! (at least 0.095 ms long) > > > > Issue was caused by wrong residue reported by pl330 driver to > > pcm_dmaengine for its cyclic dma transfers. > > > > The pl330_tx_status(), residue reporting function, used a "last" flag in > > a descriptor to indicate that there is no more data to send. > > > > The pl330_tx_submit() iterated over descriptors trying to remove this > > flag from them and then mark last descriptor as "last". However when > > iterating it actually removed the flag not from descriptors but always > > from last of it (and then reset it). Thus effectively once some > > descriptor was marked as last, then it stayed like this forever causing > > residue to be reported too low. > > > > Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@xxxxxxxxx> > > Fixes: aee4d1fac887 ("dmaengine: pl330: improve pl330_tx_status() function") > > Cc: <stable@xxxxxxxxxxxxxxx> > > Reported-by: gabriel@xxxxxxxxx > > Suggested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > > Gabriel, could you give this patch a try? It helped for my Odroid XU3, > which has the same audio codec. Nevertheless it would be great to hear > that it solves the initial bug report. So is there a word on what finally fixes this -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html