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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * OSS compatible sequencer driver4 *5 * seq_oss_writeq.c - write queue and sync6 *7 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>8 */9 10#include "seq_oss_writeq.h"11#include "seq_oss_event.h"12#include "seq_oss_timer.h"13#include <sound/seq_oss_legacy.h>14#include "../seq_lock.h"15#include "../seq_clientmgr.h"16#include <linux/wait.h>17#include <linux/slab.h>18#include <linux/sched/signal.h>19 20 21/*22 * create a write queue record23 */24struct seq_oss_writeq *25snd_seq_oss_writeq_new(struct seq_oss_devinfo *dp, int maxlen)26{27 struct seq_oss_writeq *q;28 struct snd_seq_client_pool pool;29 30 q = kzalloc(sizeof(*q), GFP_KERNEL);31 if (!q)32 return NULL;33 q->dp = dp;34 q->maxlen = maxlen;35 spin_lock_init(&q->sync_lock);36 q->sync_event_put = 0;37 q->sync_time = 0;38 init_waitqueue_head(&q->sync_sleep);39 40 memset(&pool, 0, sizeof(pool));41 pool.client = dp->cseq;42 pool.output_pool = maxlen;43 pool.output_room = maxlen / 2;44 45 snd_seq_oss_control(dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);46 47 return q;48}49 50/*51 * delete the write queue52 */53void54snd_seq_oss_writeq_delete(struct seq_oss_writeq *q)55{56 if (q) {57 snd_seq_oss_writeq_clear(q); /* to be sure */58 kfree(q);59 }60}61 62 63/*64 * reset the write queue65 */66void67snd_seq_oss_writeq_clear(struct seq_oss_writeq *q)68{69 struct snd_seq_remove_events reset;70 71 memset(&reset, 0, sizeof(reset));72 reset.remove_mode = SNDRV_SEQ_REMOVE_OUTPUT; /* remove all */73 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_REMOVE_EVENTS, &reset);74 75 /* wake up sleepers if any */76 snd_seq_oss_writeq_wakeup(q, 0);77}78 79/*80 * wait until the write buffer has enough room81 */82int83snd_seq_oss_writeq_sync(struct seq_oss_writeq *q)84{85 struct seq_oss_devinfo *dp = q->dp;86 abstime_t time;87 88 time = snd_seq_oss_timer_cur_tick(dp->timer);89 if (q->sync_time >= time)90 return 0; /* already finished */91 92 if (! q->sync_event_put) {93 struct snd_seq_event ev;94 union evrec *rec;95 96 /* put echoback event */97 memset(&ev, 0, sizeof(ev));98 ev.flags = 0;99 ev.type = SNDRV_SEQ_EVENT_ECHO;100 ev.time.tick = time;101 /* echo back to itself */102 snd_seq_oss_fill_addr(dp, &ev, dp->addr.client, dp->addr.port);103 rec = (union evrec *)&ev.data;104 rec->t.code = SEQ_SYNCTIMER;105 rec->t.time = time;106 q->sync_event_put = 1;107 snd_seq_kernel_client_enqueue(dp->cseq, &ev, NULL, true);108 }109 110 wait_event_interruptible_timeout(q->sync_sleep, ! q->sync_event_put, HZ);111 if (signal_pending(current))112 /* interrupted - return 0 to finish sync */113 q->sync_event_put = 0;114 if (! q->sync_event_put || q->sync_time >= time)115 return 0;116 return 1;117}118 119/*120 * wake up sync - echo event was catched121 */122void123snd_seq_oss_writeq_wakeup(struct seq_oss_writeq *q, abstime_t time)124{125 unsigned long flags;126 127 spin_lock_irqsave(&q->sync_lock, flags);128 q->sync_time = time;129 q->sync_event_put = 0;130 wake_up(&q->sync_sleep);131 spin_unlock_irqrestore(&q->sync_lock, flags);132}133 134 135/*136 * return the unused pool size137 */138int139snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q)140{141 struct snd_seq_client_pool pool;142 pool.client = q->dp->cseq;143 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);144 return pool.output_free;145}146 147 148/*149 * set output threshold size from ioctl150 */151void152snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int val)153{154 struct snd_seq_client_pool pool;155 pool.client = q->dp->cseq;156 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);157 pool.output_room = val;158 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);159}160 161