On Mon, Feb 10, 2014 at 4:24 AM, Michal Šmucr <msm...@gmail.com> wrote:
> Hello, > > i would like to ask you for experience with USB audio interfaces and BBB. > I'm having trouble with BBB (rev. A6A) and audio playback with > snd-usb-audio under higher interrupt loads. > If i play audio through USB interface and for instance simultaneously > transferring data from network mount, i will get audio dropouts. At first > it is occasional thing and sounds like few milliseconds pops, but after > while it happens more often and leading to serious stops at playback. > It is not completely possible to avoid this situation in desired usage > (MPD based network audio player) as this happens for instance during > library update, when MPD is rereading tags from all songs. > > - it occurs more often during streaming of high bitrate audio (eg. > uncompressed stereo 176.4kHz) > - ALSA driver access optimization doesn't help - memory mapped, different > buffer and period lengths. > - forcing PIO mode with CONFIG_MUSB_PIO_ONLY doesn't help > - just for test i also tried network access through second USB port > (virtual USB eth. interface) to exclude TI ethernet driver, but it is same. > - it doesn't seems to be userspace CPU usage issue (tried to generate CPU > load with fio and it didn't produce dropouts) > - system doesn't print any other warnings or errors except of Xruns from > ALSA layer. > - I've tried several distributions with kernels 3.8.13 (Angstrom, > Volumio), 3.12.9 (Voyage), 3.13 (development version of Debian Jessie from > RobertCNelson > image). > - just for completeness, it is not issue of my USB interfaces (works great > with other Linux systems and some are not bus powered to exclude possible > issues with insufficient power from BBB USB port) > > My quick steps to reproduce.. initiate playback of hi-res audio wav from > mmc with aplay and simultaneously open several parallel network TCP > connections with iperf. > > Can anybody confirm me this issue with BBB? Do you have some tips, what to > try next? > Can you please retry with: > > Kind regards, > > Michal > > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > -- Robert Nelson http://www.rcn-ee.com/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
