Disconnecting audio device from USB-C port causes macOS Sierra to hang during shutdown
I've found that disconnecting and reconnecting an audio device from a USB-C port, especially while an app is playing audio, causes macOS to go into a weird state where it's unable to recognize the audio device when reconnected (no audio device appears in System Preferences > Sound).
The only way to resolve is a reboot - however, rebooting in this state always causes macOS to hang during the shutdown process.
To reproduce the issue:
- Connect USB 2.0 audio device to a USB-C port on a Mac (using a USB-C to USB adaptor)
- Play some audio in any app (doesn't matter which, iTunes will do)
- Disconnect (unplug) the audio device while audio is playing
- Reconnect the audio device
Expected result: The audio device re-appears in System Preferences > Sound, and works normally.
Actual result: The audio device sometimes fails to appear in System Preferences > Sound. When this happens, the only way to make it appear again is by rebooting. However rebooting causes macOS to hang during shutdown, showing a black screen with a frozen pointer. You then have to do a "hard" shutdown by holding the power button.
It sometimes takes several attempts to reproduce the issue.
I'm running macOS Sierra 10.12.4 on a late 2016 MacBook Pro, with an external USB 2.0 audio interface (RME Babyface Pro), and I can reproduce the problem using Apple's own USB-C to USB (Type A) adaptor to connect the audio device (and nothing else) to the MacBook Pro.
I contacted the audio device vendor (RME), they said it's a problem on Apple's side.
Has anyone else noticed this?
MacBook Pro (15-inch, Late 2016), macOS Sierra (10.12.4), null
