sound/core/control.c

48 	struct snd_ctl_file *ctl;
69 	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
70 	if (ctl == NULL) {
74 	INIT_LIST_HEAD(&ctl->events);
75 	init_waitqueue_head(&ctl->change_sleep);
76 	spin_lock_init(&ctl->read_lock);
77 	ctl->card = card;
79 		ctl->preferred_subdevice[i] = -1;
80 	ctl->pid = get_pid(task_pid(current));
81 	file->private_data = ctl;
83 		list_add_tail(&ctl->list, &card->ctl_files);
97 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
101 	guard(spinlock_irqsave)(&ctl->read_lock);
102 	while (!list_empty(&ctl->events)) {
103 		cread = snd_kctl_event(ctl->events.next);
112 	struct snd_ctl_file *ctl;
116 	ctl = file->private_data;
118 	card = ctl->card;
121 		list_del(&ctl->list);
126 				if (control->vd[idx].owner == ctl)
130 	snd_fasync_free(ctl->fasync);
131 	snd_ctl_empty_read_queue(ctl);
132 	put_pid(ctl->pid);
133 	kfree(ctl);
143  * @id: the ctl element id to send notification
152 	struct snd_ctl_file *ctl;
164 	list_for_each_entry(ctl, &card->ctl_files, list) {
165 		if (!ctl->subscribed)
167 		scoped_guard(spinlock, &ctl->read_lock) {
168 			list_for_each_entry(ev, &ctl->events, list) {
178 				list_add_tail(&ev->list, &ctl->events);
183 			wake_up(&ctl->change_sleep);
185 		snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN);
379 /* Compute a hash key for the corresponding ctl id
399 /* add hash entries to numid and ctl xarray tables */
897 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
1037 /* check whether the given integer ctl value is valid */
1158 			       struct snd_ctl_file *ctl)
1179 			if (vd->owner == ctl)
1192 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
1195 	struct snd_card *card = ctl->card;
1202 	return __snd_ctl_elem_info(card, kctl, info, ctl);
1205 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
1213 	result = snd_ctl_elem_info(ctl, &info);
1424 // check whether the addition (in bytes) of user ctl element may overflow the limit.
1924 	struct snd_ctl_file *ctl;
1931 	ctl = file->private_data;
1932 	card = ctl->card;
1939 		return snd_ctl_card_info(card, ctl, cmd, argp);
1943 		return snd_ctl_elem_info_user(ctl, argp);
1947 		return snd_ctl_elem_write_user(ctl, argp);
1949 		return snd_ctl_elem_lock(ctl, argp);
1951 		return snd_ctl_elem_unlock(ctl, argp);
1953 		return snd_ctl_elem_add_user(ctl, argp, 0);
1955 		return snd_ctl_elem_add_user(ctl, argp, 1);
1957 		return snd_ctl_elem_remove(ctl, argp);
1959 		return snd_ctl_subscribe_events(ctl, ip);
1961 		scoped_guard(rwsem_read, &ctl->card->controls_rwsem)
1962 			err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1965 		scoped_guard(rwsem_write, &ctl->card->controls_rwsem)
1966 			err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1969 		scoped_guard(rwsem_write, &ctl->card->controls_rwsem)
1970 			err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1980 		err = p->fioctl(card, ctl, cmd, arg);
1991 	struct snd_ctl_file *ctl;
1995 	ctl = file->private_data;
1996 	if (snd_BUG_ON(!ctl || !ctl->card))
1998 	if (!ctl->subscribed)
2002 	spin_lock_irq(&ctl->read_lock);
2006 		while (list_empty(&ctl->events)) {
2013 			add_wait_queue(&ctl->change_sleep, &wait);
2015 			spin_unlock_irq(&ctl->read_lock);
2017 			remove_wait_queue(&ctl->change_sleep, &wait);
2018 			if (ctl->card->shutdown)
2022 			spin_lock_irq(&ctl->read_lock);
2024 		kev = snd_kctl_event(ctl->events.next);
2029 		spin_unlock_irq(&ctl->read_lock);
2035 		spin_lock_irq(&ctl->read_lock);
2041 	spin_unlock_irq(&ctl->read_lock);
2049 	struct snd_ctl_file *ctl;
2051 	ctl = file->private_data;
2052 	if (!ctl->subscribed)
2054 	poll_wait(file, &ctl->change_sleep, wait);
2057 	if (!list_empty(&ctl->events))
2160 	struct snd_ctl_file *ctl;
2162 	ctl = file->private_data;
2163 	return snd_fasync_helper(fd, file, on, &ctl->fasync);
2322 	struct snd_ctl_file *ctl;
2325 		list_for_each_entry(ctl, &card->ctl_files, list) {
2326 			wake_up(&ctl->change_sleep);
2327 			snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR);