https://bugzilla.kernel.org/show_bug.cgi?id=219111 --- Comment #36 from Alan Stern (stern@xxxxxxxxxxxxxxxxxxx) --- It looks like the Xone:23C can operate in two different modes, and it decides during the initial startup which mode it will use. The first mode (what you get with old_scheme_first=N) exposes a single configuration, which has a USB audio class 1 interface and 2-channel stereo in/out. The second mode (what you get with old_scheme_first=Y) exposes two configurations. The first config is the same as the one described above, but the second config has a USB audio class 2 interface with 4-channel "stereo" in/out. The problem is how to make the device go into its second mode. Your Windows packet captures don't show this happening. In fact, they do show the device in its first mode, using the only configuration in that mode, so it shouldn't be doing 4-channel I/O at all! I don't understand that. The only way we know to put the device into the second mode is to set old_scheme_first to Y. Maybe this doesn't have to be done before the device initially starts up; you may find that resetting the device while old_scheme_first is Y will cause it to go into the second mode, even if it was in the first mode before. You could try that to see if it works. If it does, the kernel could be changed to make this happen automatically. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.