sound/core/seq/oss/seq_oss_writeq.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OSS compatible sequencer driver
   4  *
   5  * seq_oss_writeq.c - write queue and sync
   6  *
   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 record
  23  */
  24 struct seq_oss_writeq *
  25 snd_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         if ((q = kzalloc(sizeof(*q), GFP_KERNEL)) == NULL)
  31                 return NULL;
  32         q->dp = dp;
  33         q->maxlen = maxlen;
  34         spin_lock_init(&q->sync_lock);
  35         q->sync_event_put = 0;
  36         q->sync_time = 0;
  37         init_waitqueue_head(&q->sync_sleep);
  38
  39         memset(&pool, 0, sizeof(pool));
  40         pool.client = dp->cseq;
  41         pool.output_pool = maxlen;
  42         pool.output_room = maxlen / 2;
  43
  44         snd_seq_oss_control(dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
  45
  46         return q;
  47 }
  48
  49 /*
  50  * delete the write queue
  51  */
  52 void
  53 snd_seq_oss_writeq_delete(struct seq_oss_writeq *q)
  54 {
  55         if (q) {
  56                 snd_seq_oss_writeq_clear(q);    /* to be sure */
  57                 kfree(q);
  58         }
  59 }
  60
  61
  62 /*
  63  * reset the write queue
  64  */
  65 void
  66 snd_seq_oss_writeq_clear(struct seq_oss_writeq *q)
  67 {
  68         struct snd_seq_remove_events reset;
  69
  70         memset(&reset, 0, sizeof(reset));
  71         reset.remove_mode = SNDRV_SEQ_REMOVE_OUTPUT; /* remove all */
  72         snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_REMOVE_EVENTS, &reset);
  73
  74         /* wake up sleepers if any */
  75         snd_seq_oss_writeq_wakeup(q, 0);
  76 }
  77
  78 /*
  79  * wait until the write buffer has enough room
  80  */
  81 int
  82 snd_seq_oss_writeq_sync(struct seq_oss_writeq *q)
  83 {
  84         struct seq_oss_devinfo *dp = q->dp;
  85         abstime_t time;
  86
  87         time = snd_seq_oss_timer_cur_tick(dp->timer);
  88         if (q->sync_time >= time)
  89                 return 0; /* already finished */
  90
  91         if (! q->sync_event_put) {
  92                 struct snd_seq_event ev;
  93                 union evrec *rec;
  94
  95                 /* put echoback event */
  96                 memset(&ev, 0, sizeof(ev));
  97                 ev.flags = 0;
  98                 ev.type = SNDRV_SEQ_EVENT_ECHO;
  99                 ev.time.tick = time;
 100                 /* echo back to itself */
 101                 snd_seq_oss_fill_addr(dp, &ev, dp->addr.client, dp->addr.port);
 102                 rec = (union evrec *)&ev.data;
 103                 rec->t.code = SEQ_SYNCTIMER;
 104                 rec->t.time = time;
 105                 q->sync_event_put = 1;
 106                 snd_seq_kernel_client_enqueue(dp->cseq, &ev, NULL, true);
 107         }
 108
 109         wait_event_interruptible_timeout(q->sync_sleep, ! q->sync_event_put, HZ);
 110         if (signal_pending(current))
 111                 /* interrupted - return 0 to finish sync */
 112                 q->sync_event_put = 0;
 113         if (! q->sync_event_put || q->sync_time >= time)
 114                 return 0;
 115         return 1;
 116 }
 117
 118 /*
 119  * wake up sync - echo event was catched
 120  */
 121 void
 122 snd_seq_oss_writeq_wakeup(struct seq_oss_writeq *q, abstime_t time)
 123 {
 124         unsigned long flags;
 125
 126         spin_lock_irqsave(&q->sync_lock, flags);
 127         q->sync_time = time;
 128         q->sync_event_put = 0;
 129         wake_up(&q->sync_sleep);
 130         spin_unlock_irqrestore(&q->sync_lock, flags);
 131 }
 132
 133
 134 /*
 135  * return the unused pool size
 136  */
 137 int
 138 snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q)
 139 {
 140         struct snd_seq_client_pool pool;
 141         pool.client = q->dp->cseq;
 142         snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
 143         return pool.output_free;
 144 }
 145
 146
 147 /*
 148  * set output threshold size from ioctl
 149  */
 150 void
 151 snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int val)
 152 {
 153         struct snd_seq_client_pool pool;
 154         pool.client = q->dp->cseq;
 155         snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool);
 156         pool.output_room = val;
 157         snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool);
 158 }
 159