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 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 guard(spinlock_irqsave)(&q->sync_lock); 126 q->sync_time = time; 127 q->sync_event_put = 0; 128 wake_up(&q->sync_sleep); 129 } 130 131 132 /* 133 * return the unused pool size 134 */ 135 int 136 snd_seq_oss_writeq_get_free_size(struct seq_oss_writeq *q) 137 { 138 struct snd_seq_client_pool pool; 139 pool.client = q->dp->cseq; 140 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool); 141 return pool.output_free; 142 } 143 144 145 /* 146 * set output threshold size from ioctl 147 */ 148 void 149 snd_seq_oss_writeq_set_output(struct seq_oss_writeq *q, int val) 150 { 151 struct snd_seq_client_pool pool; 152 pool.client = q->dp->cseq; 153 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_GET_CLIENT_POOL, &pool); 154 pool.output_room = val; 155 snd_seq_oss_control(q->dp, SNDRV_SEQ_IOCTL_SET_CLIENT_POOL, &pool); 156 } 157 158