[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>

1 files changed, 11 insertions, 7 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);