On Sun, 07 Jun 2020 15:39:59 +0200, Laurence Tratt wrote: > > Hello, > > I've found an interesting issue with an SSL2+ audio interface -- it plays and > records fine (and, for the money, the sound quality is excellent!), but > recording slowly but surely drifts over time. For example, if I record a > click track in Audacity (or Ardour), play it through the interface and record > it, and then line up the start of the recorded click track with the original, > the two tracks will be around 5ms out of alignment after 30s. Interestingly, > this problem does not happen with OpenBSD, where the two tracks line up > precisely. > > My guess is that the problem is to do with implicit feedback in endpoints. I > wondered if the problem was the same as with the MOTU M4, but enabling that > quirk for the SSL2+ introduced some crackle, but didn't change the drift. > > I'm attaching a) the alsa-info file b) output from OpenBSD's kernel with > debugging in the USB audio driver turned on in case that gives some clues as > to what the two OS's and drivers might be doing differently. If anyone has > any suggestions for how this problem might be addressed, I would be very > grateful! The recent change in USB-audio might help for a case like yours. Try my sound git tree (for-linus branch) or Linus' tree. The former should be pullable onto 5.7 kernel cleanly. thanks, Takashi
