[PATCH] ALSA: Fix sysfs breakage

The recent change for a new sysfs tree with card* object breaks the
/sys/class/sound tree if CONFIG_SYSFS_DEPRECATED is enabled.
The device in each entry doesn't point the correct device object:

  /sys/class/sound
  ...
  |-- pcmC0D0c
  |   |-- dev
  |   |-- device -> ../../../class/sound/card0
  |   |-- pcm_class
  |   |-- power
  |   |   `-- wakeup
  |   |-- subsystem -> ../../../class/sound
  |   `-- uevent

Also, this change breaks some drivers (like sound/arm/*) referring
card->dev directly to obtain the device object for memory handling.

This patch reverts the semantics of card->dev to the former version,
which points to a real device object.  The card* object is stored in a
new card->card_dev field, instead.  The device parent is chosen either
card->dev or card->card_dev according to CONFIG_SYSFS_DEPRECATED to
keep the tree compatibility.
Also, card* isn't created if CONFIG_SYSFS_DEPRECATED is enabled.  The
reason of card* object is a root of all beloing devices, and it makes
little sense if each sound device points to the real device object
directly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Monty Montgomery <xiphmont@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 13 insertions, 13 deletions

diff --git a/sound/core/init.c b/sound/core/init.c
index 6152a75..a4cc6b1 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -361,8 +361,10 @@ static int snd_card_do_free(struct snd_card *card)
 		snd_printk(KERN_WARNING "unable to free card info\n");
 		/* Not fatal error */
 	}
-	if (card->dev)
-		device_unregister(card->dev);
+#ifndef CONFIG_SYSFS_DEPRECATED
+	if (card->card_dev)
+		device_unregister(card->card_dev);
+#endif
 	kfree(card);
 	return 0;
 }
@@ -497,12 +499,14 @@ int snd_card_register(struct snd_card *card)
 	int err;
 
 	snd_assert(card != NULL, return -EINVAL);
-	if (!card->dev) {
-		card->dev = device_create(sound_class, card->parent, 0,
-					  "card%i", card->number);
-		if (IS_ERR(card->dev))
-			card->dev = NULL;
+#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;
 	}
+#endif
 	if ((err = snd_device_register_all(card)) < 0)
 		return err;
 	mutex_lock(&snd_card_mutex);
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 2827420..82a61c6 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -238,7 +238,7 @@ int snd_register_device(int type, struct snd_card *card, int dev,
 {
 	int minor;
 	struct snd_minor *preg;
-	struct device *device = NULL;
+	struct device *device = snd_card_get_device_link(card);
 
 	snd_assert(name, return -EINVAL);
 	preg = kmalloc(sizeof *preg, GFP_KERNEL);
@@ -263,8 +263,6 @@ int snd_register_device(int type, struct snd_card *card, int dev,
 		return minor;
 	}
 	snd_minors[minor] = preg;
-	if (card)
-		device = card->dev;
 	preg->dev = device_create(sound_class, device, MKDEV(major, minor),
 				  "%s", name);
 	if (preg->dev)
diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c
index b2fc40a..4566df4 100644
--- a/sound/core/sound_oss.c
+++ b/sound/core/sound_oss.c
@@ -106,7 +106,7 @@ int snd_register_oss_device(int type, struct snd_card *card, int dev,
 	int cidx = SNDRV_MINOR_OSS_CARD(minor);
 	int track2 = -1;
 	int register1 = -1, register2 = -1;
-	struct device *carddev = NULL;
+	struct device *carddev = snd_card_get_device_link(card);
 
 	if (card && card->number >= 8)
 		return 0; /* ignore silently */
@@ -134,8 +134,6 @@ int snd_register_oss_device(int type, struct snd_card *card, int dev,
 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
 		break;
 	}
-	if (card)
-		carddev = card->dev;
 	register1 = register_sound_special_device(f_ops, minor, carddev);
 	if (register1 != minor)
 		goto __end;