forked from Minki/linux
58647286ab
Use of this function ended with commits3e58c868db
("staging: line6: drop midi_mask_receive") andaf89d2897a
("staging: line6: drop midi_mask_transmit".) [Removed the corresponding line in midibuf.h, too -- tiwai] Signed-off-by: Chris Rorvick <chris@rorvick.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
253 lines
5.3 KiB
C
253 lines
5.3 KiB
C
/*
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* Line 6 Linux USB driver
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*
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* Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2.
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*
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*/
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#include <linux/slab.h>
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#include "midibuf.h"
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static int midibuf_message_length(unsigned char code)
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{
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int message_length;
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if (code < 0x80)
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message_length = -1;
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else if (code < 0xf0) {
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static const int length[] = { 3, 3, 3, 3, 2, 2, 3 };
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message_length = length[(code >> 4) - 8];
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} else {
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/*
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Note that according to the MIDI specification 0xf2 is
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the "Song Position Pointer", but this is used by Line 6
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to send sysex messages to the host.
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*/
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static const int length[] = { -1, 2, -1, 2, -1, -1, 1, 1, 1, 1,
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1, 1, 1, -1, 1, 1
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};
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message_length = length[code & 0x0f];
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}
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return message_length;
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}
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static int midibuf_is_empty(struct midi_buffer *this)
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{
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return (this->pos_read == this->pos_write) && !this->full;
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}
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static int midibuf_is_full(struct midi_buffer *this)
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{
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return this->full;
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}
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void line6_midibuf_reset(struct midi_buffer *this)
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{
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this->pos_read = this->pos_write = this->full = 0;
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this->command_prev = -1;
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}
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int line6_midibuf_init(struct midi_buffer *this, int size, int split)
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{
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this->buf = kmalloc(size, GFP_KERNEL);
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if (this->buf == NULL)
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return -ENOMEM;
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this->size = size;
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this->split = split;
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line6_midibuf_reset(this);
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return 0;
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}
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int line6_midibuf_bytes_free(struct midi_buffer *this)
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{
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return
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midibuf_is_full(this) ?
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0 :
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(this->pos_read - this->pos_write + this->size - 1) % this->size +
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1;
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}
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int line6_midibuf_bytes_used(struct midi_buffer *this)
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{
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return
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midibuf_is_empty(this) ?
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0 :
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(this->pos_write - this->pos_read + this->size - 1) % this->size +
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1;
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}
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int line6_midibuf_write(struct midi_buffer *this, unsigned char *data,
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int length)
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{
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int bytes_free;
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int length1, length2;
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int skip_active_sense = 0;
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if (midibuf_is_full(this) || (length <= 0))
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return 0;
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/* skip trailing active sense */
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if (data[length - 1] == 0xfe) {
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--length;
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skip_active_sense = 1;
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}
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bytes_free = line6_midibuf_bytes_free(this);
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if (length > bytes_free)
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length = bytes_free;
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if (length > 0) {
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length1 = this->size - this->pos_write;
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if (length < length1) {
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/* no buffer wraparound */
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memcpy(this->buf + this->pos_write, data, length);
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this->pos_write += length;
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} else {
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/* buffer wraparound */
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length2 = length - length1;
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memcpy(this->buf + this->pos_write, data, length1);
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memcpy(this->buf, data + length1, length2);
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this->pos_write = length2;
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}
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if (this->pos_write == this->pos_read)
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this->full = 1;
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}
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return length + skip_active_sense;
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}
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int line6_midibuf_read(struct midi_buffer *this, unsigned char *data,
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int length)
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{
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int bytes_used;
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int length1, length2;
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int command;
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int midi_length;
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int repeat = 0;
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int i;
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/* we need to be able to store at least a 3 byte MIDI message */
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if (length < 3)
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return -EINVAL;
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if (midibuf_is_empty(this))
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return 0;
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bytes_used = line6_midibuf_bytes_used(this);
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if (length > bytes_used)
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length = bytes_used;
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length1 = this->size - this->pos_read;
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/* check MIDI command length */
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command = this->buf[this->pos_read];
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if (command & 0x80) {
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midi_length = midibuf_message_length(command);
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this->command_prev = command;
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} else {
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if (this->command_prev > 0) {
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int midi_length_prev =
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midibuf_message_length(this->command_prev);
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if (midi_length_prev > 0) {
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midi_length = midi_length_prev - 1;
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repeat = 1;
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} else
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midi_length = -1;
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} else
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midi_length = -1;
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}
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if (midi_length < 0) {
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/* search for end of message */
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if (length < length1) {
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/* no buffer wraparound */
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for (i = 1; i < length; ++i)
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if (this->buf[this->pos_read + i] & 0x80)
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break;
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midi_length = i;
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} else {
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/* buffer wraparound */
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length2 = length - length1;
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for (i = 1; i < length1; ++i)
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if (this->buf[this->pos_read + i] & 0x80)
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break;
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if (i < length1)
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midi_length = i;
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else {
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for (i = 0; i < length2; ++i)
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if (this->buf[i] & 0x80)
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break;
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midi_length = length1 + i;
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}
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}
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if (midi_length == length)
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midi_length = -1; /* end of message not found */
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}
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if (midi_length < 0) {
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if (!this->split)
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return 0; /* command is not yet complete */
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} else {
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if (length < midi_length)
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return 0; /* command is not yet complete */
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length = midi_length;
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}
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if (length < length1) {
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/* no buffer wraparound */
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memcpy(data + repeat, this->buf + this->pos_read, length);
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this->pos_read += length;
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} else {
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/* buffer wraparound */
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length2 = length - length1;
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memcpy(data + repeat, this->buf + this->pos_read, length1);
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memcpy(data + repeat + length1, this->buf, length2);
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this->pos_read = length2;
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}
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if (repeat)
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data[0] = this->command_prev;
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this->full = 0;
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return length + repeat;
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}
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int line6_midibuf_ignore(struct midi_buffer *this, int length)
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{
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int bytes_used = line6_midibuf_bytes_used(this);
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if (length > bytes_used)
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length = bytes_used;
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this->pos_read = (this->pos_read + length) % this->size;
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this->full = 0;
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return length;
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}
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void line6_midibuf_destroy(struct midi_buffer *this)
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{
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kfree(this->buf);
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this->buf = NULL;
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}
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