As this issue was very annoying, I bought a headset-adapter and switched away from using a USB audio device to using the built-in audio adapter of my Thinkpad X121e, so this issue was off my radar. Sorry for the lack of feedback. I've just given the latest kernel a test and it still happens, which is to be expected, given that my device is connected to an OHCI-controller, not EHCI. I'll give Alan's latest OHCI-patch a try.
As this issue was very annoying, I bought a headset-adapter and switched away from using a USB audio device to using the built-in audio adapter of my Thinkpad X121e, so this issue was off my radar. Sorry for the lack of feedback. I've just given the latest kernel a test and it still happens, which is to be expected, given that my device is connected to an OHCI-controller, not EHCI. I'll give Alan's latest OHCI-patch a try.