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 <[email protected]>
   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         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 queue
  52  */
  53 void
  54 snd_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 queue
  65  */
  66 void
  67 snd_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 room
  81  */
  82 int
  83 snd_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 catched
 121  */
 122 void
 123 snd_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 size
 137  */
 138 int
 139 snd_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 ioctl
 150  */
 151 void
 152 snd_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