1 files changed, 378 insertions, 226 deletions

diff --git a/sound/core/init.c b/sound/core/init.c
index e3338d6071e..7bdfd19e24a 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -21,22 +21,34 @@
 
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/device.h>
 #include <linux/file.h>
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/ctype.h>
 #include <linux/pm.h>
+#include <linux/completion.h>
 
 #include <sound/core.h>
 #include <sound/control.h>
 #include <sound/info.h>
 
+/* monitor files for graceful shutdown (hotplug) */
+struct snd_monitor_file {
+	struct file *file;
+	const struct file_operations *disconnected_f_op;
+	struct list_head shutdown_list;	/* still need to shutdown */
+	struct list_head list;	/* link of monitor files */
+};
+
 static DEFINE_SPINLOCK(shutdown_lock);
 static LIST_HEAD(shutdown_files);
 
 static const struct file_operations snd_shutdown_f_ops;
 
-static unsigned int snd_cards_lock;	/* locked for registering/using */
+/* locked for registering/using */
+static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
 struct snd_card *snd_cards[SNDRV_CARDS];
 EXPORT_SYMBOL(snd_cards);
 
@@ -46,17 +58,24 @@ static char *slots[SNDRV_CARDS];
 module_param_array(slots, charp, NULL, 0444);
 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
 
-/* return non-zero if the given index is already reserved for another
+/* return non-zero if the given index is reserved for the given
  * module via slots option
  */
-static int module_slot_mismatch(struct module *module, int idx)
+static int module_slot_match(struct module *module, int idx)
 {
+	int match = 1;
 #ifdef MODULE
-	char *s1, *s2;
-	if (!module || !module->name || !slots[idx])
+	const char *s1, *s2;
+
+	if (!module || !*module->name || !slots[idx])
 		return 0;
-	s1 = slots[idx];
-	s2 = module->name;
+
+	s1 = module->name;
+	s2 = slots[idx];
+	if (*s2 == '!') {
+		match = 0; /* negative match */
+		s2++;
+	}
 	/* compare module name strings
 	 * hyphens are handled as equivalent with underscore
 	 */
@@ -68,15 +87,15 @@ static int module_slot_mismatch(struct module *module, int idx)
 		if (c2 == '-')
 			c2 = '_';
 		if (c1 != c2)
-			return 1;
+			return !match;
 		if (!c1)
 			break;
 	}
-#endif
-	return 0;
+#endif /* MODULE */
+	return match;
 }
 
-#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
 #endif
@@ -94,11 +113,11 @@ static inline int init_info_for_card(struct snd_card *card)
 	struct snd_info_entry *entry;
 
 	if ((err = snd_info_card_register(card)) < 0) {
-		snd_printd("unable to create card info\n");
+		dev_dbg(card->dev, "unable to create card info\n");
 		return err;
 	}
 	if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
-		snd_printd("unable to create card entry\n");
+		dev_dbg(card->dev, "unable to create card entry\n");
 		return err;
 	}
 	entry->c.text.read = snd_card_id_read;
@@ -113,101 +132,146 @@ static inline int init_info_for_card(struct snd_card *card)
 #define init_info_for_card(card)
 #endif
 
+static int check_empty_slot(struct module *module, int slot)
+{
+	return !slots[slot] || !*slots[slot];
+}
+
+/* return an empty slot number (>= 0) found in the given bitmask @mask.
+ * @mask == -1 == 0xffffffff means: take any free slot up to 32
+ * when no slot is available, return the original @mask as is.
+ */
+static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
+				 struct module *module)
+{
+	int slot;
+
+	for (slot = 0; slot < SNDRV_CARDS; slot++) {
+		if (slot < 32 && !(mask & (1U << slot)))
+			continue;
+		if (!test_bit(slot, snd_cards_lock)) {
+			if (check(module, slot))
+				return slot; /* found */
+		}
+	}
+	return mask; /* unchanged */
+}
+
+static int snd_card_do_free(struct snd_card *card);
+static const struct attribute_group *card_dev_attr_groups[];
+
+static void release_card_device(struct device *dev)
+{
+	snd_card_do_free(dev_to_snd_card(dev));
+}
+
 /**
  *  snd_card_new - create and initialize a soundcard structure
+ *  @parent: the parent device object
  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
  *  @xid: card identification (ASCII string)
  *  @module: top level module for locking
  *  @extra_size: allocate this extra size after the main soundcard structure
+ *  @card_ret: the pointer to store the created card instance
  *
  *  Creates and initializes a soundcard structure.
  *
- *  Returns kmallocated snd_card structure. Creates the ALSA control interface
- *  (which is blocked until snd_card_register function is called).
+ *  The function allocates snd_card instance via kzalloc with the given
+ *  space for the driver to use freely.  The allocated struct is stored
+ *  in the given card_ret pointer.
+ *
+ *  Return: Zero if successful or a negative error code.
  */
-struct snd_card *snd_card_new(int idx, const char *xid,
-			 struct module *module, int extra_size)
+int snd_card_new(struct device *parent, int idx, const char *xid,
+		    struct module *module, int extra_size,
+		    struct snd_card **card_ret)
 {
 	struct snd_card *card;
 	int err;
 
+	if (snd_BUG_ON(!card_ret))
+		return -EINVAL;
+	*card_ret = NULL;
+
 	if (extra_size < 0)
 		extra_size = 0;
 	card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
-	if (card == NULL)
-		return NULL;
-	if (xid) {
-		if (!snd_info_check_reserved_words(xid))
-			goto __error;
+	if (!card)
+		return -ENOMEM;
+	if (extra_size > 0)
+		card->private_data = (char *)card + sizeof(struct snd_card);
+	if (xid)
 		strlcpy(card->id, xid, sizeof(card->id));
-	}
 	err = 0;
 	mutex_lock(&snd_card_mutex);
-	if (idx < 0) {
-		int idx2;
-		for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
-			/* idx == -1 == 0xffff means: take any free slot */
-			if (~snd_cards_lock & idx & 1<<idx2) {
-				if (module_slot_mismatch(module, idx2))
-					continue;
-				idx = idx2;
-				if (idx >= snd_ecards_limit)
-					snd_ecards_limit = idx + 1;
-				break;
-			}
-	} else {
-		 if (idx < snd_ecards_limit) {
-			if (snd_cards_lock & (1 << idx))
-				err = -EBUSY;	/* invalid */
-		} else {
-			if (idx < SNDRV_CARDS)
-				snd_ecards_limit = idx + 1; /* increase the limit */
-			else
-				err = -ENODEV;
-		}
-	}
-	if (idx < 0 || err < 0) {
+	if (idx < 0) /* first check the matching module-name slot */
+		idx = get_slot_from_bitmask(idx, module_slot_match, module);
+	if (idx < 0) /* if not matched, assign an empty slot */
+		idx = get_slot_from_bitmask(idx, check_empty_slot, module);
+	if (idx < 0)
+		err = -ENODEV;
+	else if (idx < snd_ecards_limit) {
+		if (test_bit(idx, snd_cards_lock))
+			err = -EBUSY;	/* invalid */
+	} else if (idx >= SNDRV_CARDS)
+		err = -ENODEV;
+	if (err < 0) {
 		mutex_unlock(&snd_card_mutex);
-		snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
+		dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
 			 idx, snd_ecards_limit - 1, err);
-		goto __error;
+		kfree(card);
+		return err;
 	}
-	snd_cards_lock |= 1 << idx;		/* lock it */
+	set_bit(idx, snd_cards_lock);		/* lock it */
+	if (idx >= snd_ecards_limit)
+		snd_ecards_limit = idx + 1; /* increase the limit */
 	mutex_unlock(&snd_card_mutex);
+	card->dev = parent;
 	card->number = idx;
 	card->module = module;
 	INIT_LIST_HEAD(&card->devices);
 	init_rwsem(&card->controls_rwsem);
 	rwlock_init(&card->ctl_files_rwlock);
+	mutex_init(&card->user_ctl_lock);
 	INIT_LIST_HEAD(&card->controls);
 	INIT_LIST_HEAD(&card->ctl_files);
 	spin_lock_init(&card->files_lock);
-	init_waitqueue_head(&card->shutdown_sleep);
+	INIT_LIST_HEAD(&card->files_list);
 #ifdef CONFIG_PM
 	mutex_init(&card->power_lock);
 	init_waitqueue_head(&card->power_sleep);
 #endif
+
+	device_initialize(&card->card_dev);
+	card->card_dev.parent = parent;
+	card->card_dev.class = sound_class;
+	card->card_dev.release = release_card_device;
+	card->card_dev.groups = card_dev_attr_groups;
+	err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
+	if (err < 0)
+		goto __error;
+
 	/* the control interface cannot be accessed from the user space until */
 	/* snd_cards_bitmask and snd_cards are set with snd_card_register */
-	if ((err = snd_ctl_create(card)) < 0) {
-		snd_printd("unable to register control minors\n");
+	err = snd_ctl_create(card);
+	if (err < 0) {
+		dev_err(parent, "unable to register control minors\n");
 		goto __error;
 	}
-	if ((err = snd_info_card_create(card)) < 0) {
-		snd_printd("unable to create card info\n");
+	err = snd_info_card_create(card);
+	if (err < 0) {
+		dev_err(parent, "unable to create card info\n");
 		goto __error_ctl;
 	}
-	if (extra_size > 0)
-		card->private_data = (char *)card + sizeof(struct snd_card);
-	return card;
+	*card_ret = card;
+	return 0;
 
       __error_ctl:
-	snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
+	snd_device_free_all(card);
       __error:
-	kfree(card);
-      	return NULL;
+	put_device(&card->card_dev);
+  	return err;
 }
-
 EXPORT_SYMBOL(snd_card_new);
 
 /* return non-zero if a card is already locked */
@@ -216,7 +280,7 @@ int snd_card_locked(int card)
 	int locked;
 
 	mutex_lock(&snd_card_mutex);
-	locked = snd_cards_lock & (1 << card);
+	locked = test_bit(card, snd_cards_lock);
 	mutex_unlock(&snd_card_mutex);
 	return locked;
 }
@@ -246,15 +310,19 @@ static int snd_disconnect_release(struct inode *inode, struct file *file)
 	list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 		if (_df->file == file) {
 			df = _df;
+			list_del_init(&df->shutdown_list);
 			break;
 		}
 	}
 	spin_unlock(&shutdown_lock);
 
-	if (likely(df))
+	if (likely(df)) {
+		if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
+			df->disconnected_f_op->fasync(-1, file, 0);
 		return df->disconnected_f_op->release(inode, file);
+	}
 
-	panic("%s(%p, %p) failed!", __FUNCTION__, inode, file);
+	panic("%s(%p, %p) failed!", __func__, inode, file);
 }
 
 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
@@ -300,7 +368,7 @@ static const struct file_operations snd_shutdown_f_ops =
  *
  *  Disconnects all APIs from the file-operations (user space).
  *
- *  Returns zero, otherwise a negative error code.
+ *  Return: Zero, otherwise a negative error code.
  *
  *  Note: The current implementation replaces all active file->f_op with special
  *        dummy file operations (they do nothing except release).
@@ -308,9 +376,11 @@ static const struct file_operations snd_shutdown_f_ops =
 int snd_card_disconnect(struct snd_card *card)
 {
 	struct snd_monitor_file *mfile;
-	struct file *file;
 	int err;
 
+	if (!card)
+		return -EINVAL;
+
 	spin_lock(&card->files_lock);
 	if (card->shutdown) {
 		spin_unlock(&card->files_lock);
@@ -322,15 +392,13 @@ int snd_card_disconnect(struct snd_card *card)
 	/* phase 1: disable fops (user space) operations for ALSA API */
 	mutex_lock(&snd_card_mutex);
 	snd_cards[card->number] = NULL;
+	clear_bit(card->number, snd_cards_lock);
 	mutex_unlock(&snd_card_mutex);
 	
 	/* phase 2: replace file->f_op with special dummy operations */
 	
 	spin_lock(&card->files_lock);
-	mfile = card->files;
-	while (mfile) {
-		file = mfile->file;
-
+	list_for_each_entry(mfile, &card->files_list, list) {
 		/* it's critical part, use endless loop */
 		/* we have no room to fail */
 		mfile->disconnected_f_op = mfile->file->f_op;
@@ -341,15 +409,13 @@ int snd_card_disconnect(struct snd_card *card)
 
 		mfile->file->f_op = &snd_shutdown_f_ops;
 		fops_get(mfile->file->f_op);
-		
-		mfile = mfile->next;
 	}
 	spin_unlock(&card->files_lock);	
 
 	/* phase 3: notify all connected devices about disconnection */
 	/* at this point, they cannot respond to any calls except release() */
 
-#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 #endif
@@ -357,9 +423,16 @@ int snd_card_disconnect(struct snd_card *card)
 	/* notify all devices that we are disconnected */
 	err = snd_device_disconnect_all(card);
 	if (err < 0)
-		snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
+		dev_err(card->dev, "not all devices for card %i can be disconnected\n", card->number);
 
 	snd_info_card_disconnect(card);
+	if (card->registered) {
+		device_del(&card->card_dev);
+		card->registered = false;
+	}
+#ifdef CONFIG_PM
+	wake_up(&card->power_sleep);
+#endif
 	return 0;	
 }
 
@@ -373,156 +446,235 @@ EXPORT_SYMBOL(snd_card_disconnect);
  *  devices automatically.  That is, you don't have to release the devices
  *  by yourself.
  *
- *  Returns zero. Frees all associated devices and frees the control
+ *  Return: Zero. Frees all associated devices and frees the control
  *  interface associated to given soundcard.
  */
 static int snd_card_do_free(struct snd_card *card)
 {
-#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 #endif
-	if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
-		snd_printk(KERN_ERR "unable to free all devices (pre)\n");
-		/* Fatal, but this situation should never occur */
-	}
-	if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
-		snd_printk(KERN_ERR "unable to free all devices (normal)\n");
-		/* Fatal, but this situation should never occur */
-	}
-	if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
-		snd_printk(KERN_ERR "unable to free all devices (post)\n");
-		/* Fatal, but this situation should never occur */
-	}
+	snd_device_free_all(card);
 	if (card->private_free)
 		card->private_free(card);
 	snd_info_free_entry(card->proc_id);
 	if (snd_info_card_free(card) < 0) {
-		snd_printk(KERN_WARNING "unable to free card info\n");
+		dev_warn(card->dev, "unable to free card info\n");
 		/* Not fatal error */
 	}
-#ifndef CONFIG_SYSFS_DEPRECATED
-	if (card->card_dev)
-		device_unregister(card->card_dev);
-#endif
+	if (card->release_completion)
+		complete(card->release_completion);
 	kfree(card);
 	return 0;
 }
 
-static int snd_card_free_prepare(struct snd_card *card)
-{
-	if (card == NULL)
-		return -EINVAL;
-	(void) snd_card_disconnect(card);
-	mutex_lock(&snd_card_mutex);
-	snd_cards[card->number] = NULL;
-	snd_cards_lock &= ~(1 << card->number);
-	mutex_unlock(&snd_card_mutex);
-#ifdef CONFIG_PM
-	wake_up(&card->power_sleep);
-#endif
-	return 0;
-}
-
 int snd_card_free_when_closed(struct snd_card *card)
 {
-	int free_now = 0;
-	int ret = snd_card_free_prepare(card);
+	int ret = snd_card_disconnect(card);
 	if (ret)
 		return ret;
-
-	spin_lock(&card->files_lock);
-	if (card->files == NULL)
-		free_now = 1;
-	else
-		card->free_on_last_close = 1;
-	spin_unlock(&card->files_lock);
-
-	if (free_now)
-		snd_card_do_free(card);
+	put_device(&card->card_dev);
 	return 0;
 }
-
 EXPORT_SYMBOL(snd_card_free_when_closed);
 
 int snd_card_free(struct snd_card *card)
 {
-	int ret = snd_card_free_prepare(card);
+	struct completion released;
+	int ret;
+
+	init_completion(&released);
+	card->release_completion = &released;
+	ret = snd_card_free_when_closed(card);
 	if (ret)
 		return ret;
-
 	/* wait, until all devices are ready for the free operation */
-	wait_event(card->shutdown_sleep, card->files == NULL);
-	snd_card_do_free(card);
+	wait_for_completion(&released);
 	return 0;
 }
-
 EXPORT_SYMBOL(snd_card_free);
 
-static void choose_default_id(struct snd_card *card)
+/* retrieve the last word of shortname or longname */
+static const char *retrieve_id_from_card_name(const char *name)
 {
-	int i, len, idx_flag = 0, loops = SNDRV_CARDS;
-	char *id, *spos;
-	
-	id = spos = card->shortname;	
-	while (*id != '\0') {
-		if (*id == ' ')
-			spos = id + 1;
-		id++;
+	const char *spos = name;
+
+	while (*name) {
+		if (isspace(*name) && isalnum(name[1]))
+			spos = name + 1;
+		name++;
 	}
+	return spos;
+}
+
+/* return true if the given id string doesn't conflict any other card ids */
+static bool card_id_ok(struct snd_card *card, const char *id)
+{
+	int i;
+	if (!snd_info_check_reserved_words(id))
+		return false;
+	for (i = 0; i < snd_ecards_limit; i++) {
+		if (snd_cards[i] && snd_cards[i] != card &&
+		    !strcmp(snd_cards[i]->id, id))
+			return false;
+	}
+	return true;
+}
+
+/* copy to card->id only with valid letters from nid */
+static void copy_valid_id_string(struct snd_card *card, const char *src,
+				 const char *nid)
+{
+	char *id = card->id;
+
+	while (*nid && !isalnum(*nid))
+		nid++;
+	if (isdigit(*nid))
+		*id++ = isalpha(*src) ? *src : 'D';
+	while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
+		if (isalnum(*nid))
+			*id++ = *nid;
+		nid++;
+	}
+	*id = 0;
+}
+
+/* Set card->id from the given string
+ * If the string conflicts with other ids, add a suffix to make it unique.
+ */
+static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
+				    const char *nid)
+{
+	int len, loops;
+	bool is_default = false;
+	char *id;
+	
+	copy_valid_id_string(card, src, nid);
 	id = card->id;
-	while (*spos != '\0' && !isalnum(*spos))
-		spos++;
-	if (isdigit(*spos))
-		*id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
-	while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
-		if (isalnum(*spos))
-			*id++ = *spos;
-		spos++;
+
+ again:
+	/* use "Default" for obviously invalid strings
+	 * ("card" conflicts with proc directories)
+	 */
+	if (!*id || !strncmp(id, "card", 4)) {
+		strcpy(id, "Default");
+		is_default = true;
 	}
-	*id = '\0';
 
-	id = card->id;
-	
-	if (*id == '\0')
-		strcpy(id, "default");
+	len = strlen(id);
+	for (loops = 0; loops < SNDRV_CARDS; loops++) {
+		char *spos;
+		char sfxstr[5]; /* "_012" */
+		int sfxlen;
 
-	while (1) {
-	      	if (loops-- == 0) {
-      			snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
-      			strcpy(card->id, card->proc_root->name);
-      			return;
-      		}
-	      	if (!snd_info_check_reserved_words(id))
-      			goto __change;
-		for (i = 0; i < snd_ecards_limit; i++) {
-			if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
-				goto __change;
-		}
-		break;
-
-	      __change:
-		len = strlen(id);
-		if (idx_flag) {
-			if (id[len-1] != '9')
-				id[len-1]++;
-			else
-				id[len-1] = 'A';
-		} else if ((size_t)len <= sizeof(card->id) - 3) {
-			strcat(id, "_1");
-			idx_flag++;
-		} else {
-			spos = id + len - 2;
-			if ((size_t)len <= sizeof(card->id) - 2)
-				spos++;
-			*spos++ = '_';
-			*spos++ = '1';
-			*spos++ = '\0';
-			idx_flag++;
-		}
+		if (card_id_ok(card, id))
+			return; /* OK */
+
+		/* Add _XYZ suffix */
+		sprintf(sfxstr, "_%X", loops + 1);
+		sfxlen = strlen(sfxstr);
+		if (len + sfxlen >= sizeof(card->id))
+			spos = id + sizeof(card->id) - sfxlen - 1;
+		else
+			spos = id + len;
+		strcpy(spos, sfxstr);
+	}
+	/* fallback to the default id */
+	if (!is_default) {
+		*id = 0;
+		goto again;
+	}
+	/* last resort... */
+	dev_err(card->dev, "unable to set card id (%s)\n", id);
+	if (card->proc_root->name)
+		strlcpy(card->id, card->proc_root->name, sizeof(card->id));
+}
+
+/**
+ *  snd_card_set_id - set card identification name
+ *  @card: soundcard structure
+ *  @nid: new identification string
+ *
+ *  This function sets the card identification and checks for name
+ *  collisions.
+ */
+void snd_card_set_id(struct snd_card *card, const char *nid)
+{
+	/* check if user specified own card->id */
+	if (card->id[0] != '\0')
+		return;
+	mutex_lock(&snd_card_mutex);
+	snd_card_set_id_no_lock(card, nid, nid);
+	mutex_unlock(&snd_card_mutex);
+}
+EXPORT_SYMBOL(snd_card_set_id);
+
+static ssize_t
+card_id_show_attr(struct device *dev,
+		  struct device_attribute *attr, char *buf)
+{
+	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+	return snprintf(buf, PAGE_SIZE, "%s\n", card->id);
+}
+
+static ssize_t
+card_id_store_attr(struct device *dev, struct device_attribute *attr,
+		   const char *buf, size_t count)
+{
+	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+	char buf1[sizeof(card->id)];
+	size_t copy = count > sizeof(card->id) - 1 ?
+					sizeof(card->id) - 1 : count;
+	size_t idx;
+	int c;
+
+	for (idx = 0; idx < copy; idx++) {
+		c = buf[idx];
+		if (!isalnum(c) && c != '_' && c != '-')
+			return -EINVAL;
+	}
+	memcpy(buf1, buf, copy);
+	buf1[copy] = '\0';
+	mutex_lock(&snd_card_mutex);
+	if (!card_id_ok(NULL, buf1)) {
+		mutex_unlock(&snd_card_mutex);
+		return -EEXIST;
 	}
+	strcpy(card->id, buf1);
+	snd_info_card_id_change(card);
+	mutex_unlock(&snd_card_mutex);
+
+	return count;
+}
+
+static DEVICE_ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
+
+static ssize_t
+card_number_show_attr(struct device *dev,
+		     struct device_attribute *attr, char *buf)
+{
+	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
+	return snprintf(buf, PAGE_SIZE, "%i\n", card->number);
 }
 
+static DEVICE_ATTR(number, S_IRUGO, card_number_show_attr, NULL);
+
+static struct attribute *card_dev_attrs[] = {
+	&dev_attr_id.attr,
+	&dev_attr_number.attr,
+	NULL
+};
+
+static struct attribute_group card_dev_attr_group = {
+	.attrs	= card_dev_attrs,
+};
+
+static const struct attribute_group *card_dev_attr_groups[] = {
+	&card_dev_attr_group,
+	NULL
+};
+
 /**
  *  snd_card_register - register the soundcard
  *  @card: soundcard structure
@@ -532,21 +684,22 @@ static void choose_default_id(struct snd_card *card)
  *  external accesses.  Thus, you should call this function at the end
  *  of the initialization of the card.
  *
- *  Returns zero otherwise a negative error code if the registrain failed.
+ *  Return: Zero otherwise a negative error code if the registration failed.
  */
 int snd_card_register(struct snd_card *card)
 {
 	int err;
 
-	snd_assert(card != NULL, return -EINVAL);
-#ifndef CONFIG_SYSFS_DEPRECATED
-	if (!card->card_dev) {
-		card->card_dev = device_create(sound_class, card->dev, 0,
-					       "card%i", card->number);
-		if (IS_ERR(card->card_dev))
-			card->card_dev = NULL;
+	if (snd_BUG_ON(!card))
+		return -EINVAL;
+
+	if (!card->registered) {
+		err = device_add(&card->card_dev);
+		if (err < 0)
+			return err;
+		card->registered = true;
 	}
-#endif
+
 	if ((err = snd_device_register_all(card)) < 0)
 		return err;
 	mutex_lock(&snd_card_mutex);
@@ -555,12 +708,22 @@ int snd_card_register(struct snd_card *card)
 		mutex_unlock(&snd_card_mutex);
 		return 0;
 	}
-	if (card->id[0] == '\0')
-		choose_default_id(card);
+	if (*card->id) {
+		/* make a unique id name from the given string */
+		char tmpid[sizeof(card->id)];
+		memcpy(tmpid, card->id, sizeof(card->id));
+		snd_card_set_id_no_lock(card, tmpid, tmpid);
+	} else {
+		/* create an id from either shortname or longname */
+		const char *src;
+		src = *card->shortname ? card->shortname : card->longname;
+		snd_card_set_id_no_lock(card, src,
+					retrieve_id_from_card_name(src));
+	}
 	snd_cards[card->number] = card;
 	mutex_unlock(&snd_card_mutex);
 	init_info_for_card(card);
-#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 #endif
@@ -683,7 +846,7 @@ int __exit snd_card_info_done(void)
  *  This function adds the component id string to the supported list.
  *  The component can be referred from the alsa-lib.
  *
- *  Returns zero otherwise a negative error code.
+ *  Return: Zero otherwise a negative error code.
  */
   
 int snd_component_add(struct snd_card *card, const char *component)
@@ -717,7 +880,7 @@ EXPORT_SYMBOL(snd_component_add);
  *  This linked-list is used to keep tracking the connection state,
  *  and to avoid the release of busy resources by hotplug.
  *
- *  Returns zero or a negative error code.
+ *  Return: zero or a negative error code.
  */
 int snd_card_file_add(struct snd_card *card, struct file *file)
 {
@@ -728,15 +891,15 @@ int snd_card_file_add(struct snd_card *card, struct file *file)
 		return -ENOMEM;
 	mfile->file = file;
 	mfile->disconnected_f_op = NULL;
-	mfile->next = NULL;
+	INIT_LIST_HEAD(&mfile->shutdown_list);
 	spin_lock(&card->files_lock);
 	if (card->shutdown) {
 		spin_unlock(&card->files_lock);
 		kfree(mfile);
 		return -ENODEV;
 	}
-	mfile->next = card->files;
-	card->files = mfile;
+	list_add(&mfile->list, &card->files_list);
+	get_device(&card->card_dev);
 	spin_unlock(&card->files_lock);
 	return 0;
 }
@@ -754,45 +917,32 @@ EXPORT_SYMBOL(snd_card_file_add);
  *  called beforehand, it processes the pending release of
  *  resources.
  *
- *  Returns zero or a negative error code.
+ *  Return: Zero or a negative error code.
  */
 int snd_card_file_remove(struct snd_card *card, struct file *file)
 {
-	struct snd_monitor_file *mfile, *pfile = NULL;
-	int last_close = 0;
+	struct snd_monitor_file *mfile, *found = NULL;
 
 	spin_lock(&card->files_lock);
-	mfile = card->files;
-	while (mfile) {
+	list_for_each_entry(mfile, &card->files_list, list) {
 		if (mfile->file == file) {
-			if (pfile)
-				pfile->next = mfile->next;
-			else
-				card->files = mfile->next;
+			list_del(&mfile->list);
+			spin_lock(&shutdown_lock);
+			list_del(&mfile->shutdown_list);
+			spin_unlock(&shutdown_lock);
+			if (mfile->disconnected_f_op)
+				fops_put(mfile->disconnected_f_op);
+			found = mfile;
 			break;
 		}
-		pfile = mfile;
-		mfile = mfile->next;
-	}
-	if (mfile && mfile->disconnected_f_op) {
-		fops_put(mfile->disconnected_f_op);
-		spin_lock(&shutdown_lock);
-		list_del(&mfile->shutdown_list);
-		spin_unlock(&shutdown_lock);
 	}
-	if (card->files == NULL)
-		last_close = 1;
 	spin_unlock(&card->files_lock);
-	if (last_close) {
-		wake_up(&card->shutdown_sleep);
-		if (card->free_on_last_close)
-			snd_card_do_free(card);
-	}
-	if (!mfile) {
-		snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
+	if (!found) {
+		dev_err(card->dev, "card file remove problem (%p)\n", file);
 		return -ENOENT;
 	}
-	kfree(mfile);
+	kfree(found);
+	put_device(&card->card_dev);
 	return 0;
 }
 
@@ -806,6 +956,8 @@ EXPORT_SYMBOL(snd_card_file_remove);
  *
  *  Waits until the power-state is changed.
  *
+ *  Return: Zero if successful, or a negative error code.
+ *
  *  Note: the power lock must be active before call.
  */
 int snd_power_wait(struct snd_card *card, unsigned int power_state)