usb/line6/playback.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Line 6 Linux USB driver
0004  *
0005  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
0006  */
0007
0008 #ifndef PLAYBACK_H
0009 #define PLAYBACK_H
0010
0011 #include <sound/pcm.h>
0012
0013 #include "driver.h"
0014
0015 /*
0016  * When the TonePort is used with jack in full duplex mode and the outputs are
0017  * not connected, the software monitor produces an ugly noise since everything
0018  * written to the output buffer (i.e., the input signal) will be repeated in
0019  * the next period (sounds like a delay effect). As a workaround, the output
0020  * buffer is cleared after the data have been read, but there must be a better
0021  * solution. Until one is found, this workaround can be used to fix the
0022  * problem.
0023  */
0024 #define USE_CLEAR_BUFFER_WORKAROUND 1
0025
0026 extern const struct snd_pcm_ops snd_line6_playback_ops;
0027
0028 extern int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm);
0029 extern int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm);
0030
0031 #endif