ALSA: control: Provide a helper to look for the preferred subdevice (23c18d4b) · Commits · 戴 / test

include/sound/control.h

+9 −2

Original line number	Original line	Diff line number	Diff line
	@@ -93,12 +93,17 @@ struct snd_kctl_event {

	struct pid;		struct pid;

			enum {
			SND_CTL_SUBDEV_PCM,
			SND_CTL_SUBDEV_RAWMIDI,
			SND_CTL_SUBDEV_ITEMS,
			};

	struct snd_ctl_file {		struct snd_ctl_file {
	struct list_head list; /* list of all control files */		struct list_head list; /* list of all control files */
	struct snd_card *card;		struct snd_card *card;
	struct pid *pid;		struct pid *pid;
	int prefer_pcm_subdevice;		int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
	int prefer_rawmidi_subdevice;
	wait_queue_head_t change_sleep;		wait_queue_head_t change_sleep;
	spinlock_t read_lock;		spinlock_t read_lock;
	struct fasync_struct *fasync;		struct fasync_struct *fasync;
	@@ -138,6 +143,8 @@ int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
	#define snd_ctl_unregister_ioctl_compat(fcn)		#define snd_ctl_unregister_ioctl_compat(fcn)
	#endif		#endif

			int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);

	static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol kctl, struct snd_ctl_elem_id id)		static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol kctl, struct snd_ctl_elem_id id)
	{		{
	return id->numid - kctl->id.numid;		return id->numid - kctl->id.numid;

sound/core/control.c

+24 −3

Original line number	Original line	Diff line number	Diff line
	@@ -50,7 +50,7 @@ static int snd_ctl_open(struct inode inode, struct file file)
	unsigned long flags;		unsigned long flags;
	struct snd_card *card;		struct snd_card *card;
	struct snd_ctl_file *ctl;		struct snd_ctl_file *ctl;
	int err;		int i, err;

	err = nonseekable_open(inode, file);		err = nonseekable_open(inode, file);
	if (err < 0)		if (err < 0)
	@@ -79,8 +79,8 @@ static int snd_ctl_open(struct inode inode, struct file file)
	init_waitqueue_head(&ctl->change_sleep);		init_waitqueue_head(&ctl->change_sleep);
	spin_lock_init(&ctl->read_lock);		spin_lock_init(&ctl->read_lock);
	ctl->card = card;		ctl->card = card;
	ctl->prefer_pcm_subdevice = -1;		for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
	ctl->prefer_rawmidi_subdevice = -1;		ctl->preferred_subdevice[i] = -1;
	ctl->pid = get_pid(task_pid(current));		ctl->pid = get_pid(task_pid(current));
	file->private_data = ctl;		file->private_data = ctl;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);		write_lock_irqsave(&card->ctl_files_rwlock, flags);
	@@ -1607,6 +1607,27 @@ static int snd_ctl_fasync(int fd, struct file * file, int on)
	return fasync_helper(fd, file, on, &ctl->fasync);		return fasync_helper(fd, file, on, &ctl->fasync);
	}		}

			/* return the preferred subdevice number if already assigned;
			* otherwise return -1
			*/
			int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
			{
			struct snd_ctl_file *kctl;
			int subdevice = -1;

			read_lock(&card->ctl_files_rwlock);
			list_for_each_entry(kctl, &card->ctl_files, list) {
			if (kctl->pid == task_pid(current)) {
			subdevice = kctl->preferred_subdevice[type];
			if (subdevice != -1)
			break;
			}
			}
			read_unlock(&card->ctl_files_rwlock);
			return subdevice;
			}
			EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);

	/*		/*
	* ioctl32 compat		* ioctl32 compat
	*/		*/

sound/core/pcm.c

+3 −12

Original line number	Original line	Diff line number	Diff line
	@@ -161,7 +161,7 @@ static int snd_pcm_control_ioctl(struct snd_card *card,

	if (get_user(val, (int __user *)arg))		if (get_user(val, (int __user *)arg))
	return -EFAULT;		return -EFAULT;
	control->prefer_pcm_subdevice = val;		control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
	return 0;		return 0;
	}		}
	}		}
	@@ -901,9 +901,8 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
	struct snd_pcm_str * pstr;		struct snd_pcm_str * pstr;
	struct snd_pcm_substream *substream;		struct snd_pcm_substream *substream;
	struct snd_pcm_runtime *runtime;		struct snd_pcm_runtime *runtime;
	struct snd_ctl_file *kctl;
	struct snd_card *card;		struct snd_card *card;
	int prefer_subdevice = -1;		int prefer_subdevice;
	size_t size;		size_t size;

	if (snd_BUG_ON(!pcm \|\| !rsubstream))		if (snd_BUG_ON(!pcm \|\| !rsubstream))
	@@ -914,15 +913,7 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
	return -ENODEV;		return -ENODEV;

	card = pcm->card;		card = pcm->card;
	read_lock(&card->ctl_files_rwlock);		prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
	list_for_each_entry(kctl, &card->ctl_files, list) {
	if (kctl->pid == task_pid(current)) {
	prefer_subdevice = kctl->prefer_pcm_subdevice;
	if (prefer_subdevice != -1)
	break;
	}
	}
	read_unlock(&card->ctl_files_rwlock);

	switch (stream) {		switch (stream) {
	case SNDRV_PCM_STREAM_PLAYBACK:		case SNDRV_PCM_STREAM_PLAYBACK:

sound/core/rawmidi.c

+2 −12

Original line number	Original line	Diff line number	Diff line
	@@ -369,7 +369,6 @@ static int snd_rawmidi_open(struct inode inode, struct file file)
	struct snd_rawmidi *rmidi;		struct snd_rawmidi *rmidi;
	struct snd_rawmidi_file *rawmidi_file = NULL;		struct snd_rawmidi_file *rawmidi_file = NULL;
	wait_queue_t wait;		wait_queue_t wait;
	struct snd_ctl_file *kctl;

	if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK))		if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK))
	return -EINVAL; /* invalid combination */		return -EINVAL; /* invalid combination */
	@@ -413,16 +412,7 @@ static int snd_rawmidi_open(struct inode inode, struct file file)
	init_waitqueue_entry(&wait, current);		init_waitqueue_entry(&wait, current);
	add_wait_queue(&rmidi->open_wait, &wait);		add_wait_queue(&rmidi->open_wait, &wait);
	while (1) {		while (1) {
	subdevice = -1;		subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_RAWMIDI);
	read_lock(&card->ctl_files_rwlock);
	list_for_each_entry(kctl, &card->ctl_files, list) {
	if (kctl->pid == task_pid(current)) {
	subdevice = kctl->prefer_rawmidi_subdevice;
	if (subdevice != -1)
	break;
	}
	}
	read_unlock(&card->ctl_files_rwlock);
	err = rawmidi_open_priv(rmidi, subdevice, fflags, rawmidi_file);		err = rawmidi_open_priv(rmidi, subdevice, fflags, rawmidi_file);
	if (err >= 0)		if (err >= 0)
	break;		break;
	@@ -862,7 +852,7 @@ static int snd_rawmidi_control_ioctl(struct snd_card *card,

	if (get_user(val, (int __user *)argp))		if (get_user(val, (int __user *)argp))
	return -EFAULT;		return -EFAULT;
	control->prefer_rawmidi_subdevice = val;		control->preferred_subdevice[SND_CTL_SUBDEV_RAWMIDI] = val;
	return 0;		return 0;
	}		}
	case SNDRV_CTL_IOCTL_RAWMIDI_INFO:		case SNDRV_CTL_IOCTL_RAWMIDI_INFO:

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