HID: cp2112: fix sleep-while-atomic

A recent commit fixing DMA-buffers on stack added a shared transfer
buffer protected by a spinlock. This is broken as the USB HID request
callbacks can sleep. Fix this up by replacing the spinlock with a mutex.

Fixes: 1ffb3c40ffb5 ("HID: cp2112: make transfer buffers DMA capable")
Cc: stable <stable@vger.kernel.org>	# 4.9
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

path: root/sound/usb/stream.h

#ifndef __USBAUDIO_STREAM_H
#define __USBAUDIO_STREAM_H

int snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
				  int iface_no);

int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
			     int stream,
			     struct audioformat *fp);

#endif /* __USBAUDIO_STREAM_H */