On Thu, 09 Jun 2016 13:38:19 +0200, Ihar Filipau wrote: > > Hi All! > > When using the dmix on ARM, the sound comes out garbled, with as if > overlapping, increasing-in-number echoes. That happens even with a > single aplay instance. > > In a forum discussion, it was suggested that ARM lacks optimized dmix > implementation. But that implies that the generic dmix code is broken, > since it is what is used on ARM/etc, but not on i386/amd64. (The forum > discussion about my particular issue: > http://unix.stackexchange.com/questions/288451/sound-corruption-echo-when-trying-to-use-alsa-dmix > ) > > Does anybody has any suggestions how to fix/avoid the dmix issue on ARM? > > Thanks. > > P.S. Versions: Linux v3.18.24, alsa-lib/-utils v1.0.29. The hardware: > FreeScale i.MX35 (ARM1136) with SGTL5000 sound chip (used in 48KHz > mode). > > P.P.S. The generic code has outdated functions for the "concurrent" > implementation with cmpxchg. The code probably could be updated, and > revised to use the C11's stdatomic.h when available. This is likely the cache coherency issue. For example, the generic dmix code works fine on x86-64 if I modify the ifdef condition (I tested now). I suppose the mmap support is broken with your device / driver. Does "aplay -Dhw -M --period-size=1024 somefile.wav" work? This should show a similar problem. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
