At Wed, 03 Apr 2013 12:15:25 +0200, David Henningsson wrote: > > Hi ALSA developers, > > Just to get your attention here on what seems to be an USB audio > regression. > > The bug is described in detail here: > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1136110?comments=all > > Quoting the bug: > > " > This bug seems to affect only a certain kind of hardware, which is > called "Asynchronous USB Digital Audio Codec (DAC)". It's said that such > a DAC hosts the clock itself (USB Device Host). An ordinary DAC, so > called "Synchronous USB DAC", uses the clock hosted by the mother board, > which is not affected by this bug. > > When this bug affects an asynchronous USB DAC, the audio played by the > DAC is constantly interrupted. The playback itself does not stop, but > the output becomes discontinous, filling with constant crackling noises, > destroying everything the DAC plays. > " > > According to the bug reporter, which seems to have done quite a bit of > research, this started between 3.8-rc6 and 3.8-rc7 as well as stable > kernels and the bug also lists a few commits which could be the cause, > none under sound/usb though. Yes, there is no commits regarding usb-audio itself between 3.8-rc6 and rc7, so the likely culprit is in drivers/usb (usually either drivers/usb/host or drivers/usb/core). There are a bunch of changes there, so further bisection would be appreciated. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
