[ALSA] Fix creation of control devices over udev

Control Midlevel,ALSA Core
Don't create control devices before the driver initialization finishes
(ALSA BTS #742).

The control device is now handled in the device list together with others
(holding the card instance as the device pointer).
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/control.h

@@ -115,10 +115,8 @@ int snd_ctl_rename_id(snd_card_t * card, snd_ctl_elem_id_t *src_id, snd_ctl_elem
 snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid);
 snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id);
 
-int snd_ctl_register(snd_card_t *card);
-int snd_ctl_disconnect(snd_card_t *card);
-int snd_ctl_can_unregister(snd_card_t *card);
-int snd_ctl_unregister(snd_card_t *card);
+int snd_ctl_create(snd_card_t *card);
+
 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
 

include/sound/core.h

@@ -49,6 +49,7 @@ struct sbus_dev;
 
 typedef enum {
 	SNDRV_DEV_TOPLEVEL =		(0*SNDRV_DEV_TYPE_RANGE_SIZE),
+	SNDRV_DEV_CONTROL,
 	SNDRV_DEV_LOWLEVEL_PRE,
 	SNDRV_DEV_LOWLEVEL_NORMAL =	(1*SNDRV_DEV_TYPE_RANGE_SIZE),
 	SNDRV_DEV_PCM,

sound/core/control.c

@@ -1274,11 +1274,11 @@ static snd_minor_t snd_ctl_reg =
 };
 
 /*
- * registration of the control device:
- * called from init.c
+ * registration of the control device
  */
-int snd_ctl_register(snd_card_t *card)
+static int snd_ctl_dev_register(snd_device_t *device)
 {
+	snd_card_t *card = device->device_data;
 	int err, cardnum;
 	char name[16];
 
@@ -1293,11 +1293,11 @@ int snd_ctl_register(snd_card_t *card)
 }
 
 /*
- * disconnection of the control device:
- * called from init.c
+ * disconnection of the control device
  */
-int snd_ctl_disconnect(snd_card_t *card)
+static int snd_ctl_dev_disconnect(snd_device_t *device)
 {
+	snd_card_t *card = device->device_data;
 	struct list_head *flist;
 	snd_ctl_file_t *ctl;
 
@@ -1312,11 +1312,11 @@ int snd_ctl_disconnect(snd_card_t *card)
 }
 
 /*
- * de-registration of the control device:
- * called from init.c
+ * de-registration of the control device
  */
-int snd_ctl_unregister(snd_card_t *card)
+static int snd_ctl_dev_unregister(snd_device_t *device)
 {
+	snd_card_t *card = device->device_data;
 	int err, cardnum;
 	snd_kcontrol_t *control;
 
@@ -1333,3 +1333,19 @@ int snd_ctl_unregister(snd_card_t *card)
 	up_write(&card->controls_rwsem);
 	return 0;
 }
+
+/*
+ * create control core:
+ * called from init.c
+ */
+int snd_ctl_create(snd_card_t *card)
+{
+	static snd_device_ops_t ops = {
+		.dev_register =	snd_ctl_dev_register,
+		.dev_disconnect = snd_ctl_dev_disconnect,
+		.dev_unregister = snd_ctl_dev_unregister
+	};
+
+	snd_assert(card != NULL, return -ENXIO);
+	return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
+}

sound/core/init.c

@@ -124,7 +124,7 @@ snd_card_t *snd_card_new(int idx, const char *xid,
 #endif
 	/* 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_register(card)) < 0) {
+	if ((err = snd_ctl_create(card)) < 0) {
 		snd_printd("unable to register control minors\n");
 		goto __error;
 	}
@@ -137,7 +137,7 @@ snd_card_t *snd_card_new(int idx, const char *xid,
 	return card;
 
       __error_ctl:
-	snd_ctl_unregister(card);
+	snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
       __error:
 	kfree(card);
       	return NULL;
@@ -216,8 +216,6 @@ int snd_card_disconnect(snd_card_t * card)
 	/* phase 3: notify all connected devices about disconnection */
 	/* at this point, they cannot respond to any calls except release() */
 
-	snd_ctl_disconnect(card);
-
 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
@@ -277,10 +275,6 @@ int snd_card_free(snd_card_t * card)
 		snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 		/* Fatal, but this situation should never occur */
 	}
-	if (snd_ctl_unregister(card) < 0) {
-		snd_printk(KERN_ERR "unable to unregister control minors\n");
-		/* Not fatal error */
-	}
 	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 */

sound/core/sound.c

@@ -228,12 +228,11 @@ int snd_register_device(int type, snd_card_t * card, int dev, snd_minor_t * reg,
 		return -EBUSY;
 	}
 	list_add_tail(&preg->list, &snd_minors_hash[SNDRV_MINOR_CARD(minor)]);
-	if (strncmp(name, "controlC", 8) || card->number >= cards_limit) {
+	if (strncmp(name, "controlC", 8) || card->number >= cards_limit)
 		devfs_mk_cdev(MKDEV(major, minor), S_IFCHR | device_mode, "snd/%s", name);
 	if (card)
 		device = card->dev;
 	class_simple_device_add(sound_class, MKDEV(major, minor), device, name);
-	}
 
 	up(&sound_mutex);
 	return 0;
@@ -263,10 +262,9 @@ int snd_unregister_device(int type, snd_card_t * card, int dev)
 		return -EINVAL;
 	}
 
-	if (strncmp(mptr->name, "controlC", 8) || card->number >= cards_limit) { /* created in sound.c */
+	if (strncmp(mptr->name, "controlC", 8) || card->number >= cards_limit) /* created in sound.c */
 		devfs_remove("snd/%s", mptr->name);
 	class_simple_device_remove(MKDEV(major, minor));
-	}
 
 	list_del(&mptr->list);
 	up(&sound_mutex);
@@ -357,10 +355,8 @@ static int __init alsa_sound_init(void)
 		return -ENOMEM;
 	}
 	snd_info_minor_register();
-	for (controlnum = 0; controlnum < cards_limit; controlnum++) {
+	for (controlnum = 0; controlnum < cards_limit; controlnum++)
 		devfs_mk_cdev(MKDEV(major, controlnum<<5), S_IFCHR | device_mode, "snd/controlC%d", controlnum);
-		class_simple_device_add(sound_class, MKDEV(major, controlnum<<5), NULL, "controlC%d", controlnum);
-	}
 #ifndef MODULE
 	printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
 #endif
@@ -371,10 +367,8 @@ static void __exit alsa_sound_exit(void)
 {
 	short controlnum;
 
-	for (controlnum = 0; controlnum < cards_limit; controlnum++) {
+	for (controlnum = 0; controlnum < cards_limit; controlnum++)
 		devfs_remove("snd/controlC%d", controlnum);
-		class_simple_device_remove(MKDEV(major, controlnum<<5));
-	}
 
 	snd_info_minor_unregister();
 	snd_info_done();