Al Viro wrote:
> BTW, snd_card_disconnect() doesn't do anything to existing mappings; smells
> like a bug, and there we do have ones with non-trivial ->mmap(). Could
> ALSA folks comment?
I don't know of any hotplug sound driver that maps memory from a device.
All hotplug buses (PCIe, USB, FireWire) involve DMAing from/to main
memory.
When a sound device is unplugged, sample transfers just stop, but the
buffer itself stays as long as the device node is kept opened. (In the
case of a capture device, that actually makes sense.)
Regards,
Clemens