On Wed, 8 May 2013, Joe Rayhawk wrote: > For what it's worth, the following -stable patch > > "ALSA: USB: adjust for changed 3.8 USB API" > c75c5ab575af7db707689cdbb5a5c458e9a034bb > > fixes the discontinuous playback on period sizes between 139 and 192, > but the discontinuous playback on period sizes between 48 and 138 has > been replaced by rather worse kernel blocking and kernel errors: > > jrayhawk@richardiv:~$ sudo tail -F -n 0 /var/log/kern.log & > [1] 4490 > jrayhawk@richardiv:~$ time perl -e 'print pack "H*", "00FF" x 2048' | aplay --period-size=192 -r 48000 -f S16_LE -c2 -D hw:0,0 > Playing raw data 'stdin' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo > > real 0m0.053s > user 0m0.008s > sys 0m0.000s > jrayhawk@richardiv:~$ time perl -e 'print pack "H*", "00FF" x 2048' | aplay --period-size=48 -r 48000 -f S16_LE -c2 -D hw:0,0 > Playing raw data 'stdin' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo > May 8 17:01:56 richardiv kernel: [ 1680.923474] cannot submit urb (err = -18) > May 8 17:01:56 richardiv kernel: [ 1680.924472] cannot submit urb (err = -18) > > real 0m10.023s > user 0m0.008s > sys 0m0.004s I don't know if you want to investigate this in any detail. If you do, please post a usbmon trace of a failed playback. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
