controlC1 no longer show up after USBDEVFS_DISCONNECT

[GitHub issues - opened]

alsa-project/alsa-lib issue #276 was opened from robertwu1:

After running the following IOCTL on some MIDI devices, the control C1 device node is gone.

~~~
struct usbdevfs_ioctl ctl;

ctl.ifno = interface; // MIDI interface
ctl.ioctl_code = USBDEVFS_DISCONNECT;
ctl.data = NULL;
return ioctl(device->fd, USBDEVFS_IOCTL, &ctl);
~~~

Under /dev/snd, the following disappears: controlC1, midiC1D0, pcmC1D0c, pcmC1D0p.

MidiControl, AudioStreaming, and AudioControl are under separate interfaces. If some of these were to disappear, I expect only midiC1D0 to disappear.

I've tested the following devices:

/dev/snd looks the same after USBDEVFS_DISCONNECT: PreSonus AudioBox 96, Alesis iO4, Komplete Audio 6.

controlC1, midiC1D0, pcmC1D0c, pcmC1D0p are gone: PreSonus Studio 26c, Yamaha AG06.

Here is a public Android bug of users having issues of this on Android: https://issuetracker.google.com/issues/251050530

Issue URL     : https://github.com/alsa-project/alsa-lib/issues/276
Repository URL: https://github.com/alsa-project/alsa-lib