[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, 15 insertions, 3 deletions

diff --git a/include/sound/core.h b/include/sound/core.h
index a994bea09cd6..521f036cce99 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -132,8 +132,10 @@ struct snd_card {
         int shutdown;                   /* this card is going down */
         int free_on_last_close;         /* free in context of file_release */
         wait_queue_head_t shutdown_sleep;
-        struct device *parent;
-        struct device *dev;
+        struct device *dev;             /* device assigned to this card */
+#ifndef CONFIG_SYSFS_DEPRECATED
+        struct device *card_dev;        /* cardX object for sysfs */
+#endif
 
 #ifdef CONFIG_PM
         unsigned int power_state;       /* power state */
@@ -191,6 +193,16 @@ struct snd_minor {
         struct device *dev;             /* device for sysfs */
 };
 
+/* return a device pointer linked to each sound device as a parent */
+static inline struct device *snd_card_get_device_link(struct snd_card *card)
+{
+#ifdef CONFIG_SYSFS_DEPRECATED
+        return card ? card->dev : NULL;
+#else
+        return card ? card->card_dev : NULL;
+#endif
+}
+
 /* sound.c */
 
 extern int snd_major;
@@ -257,7 +269,7 @@ int snd_card_file_add(struct snd_card *card, struct file *file);
 int snd_card_file_remove(struct snd_card *card, struct file *file);
 
 #ifndef snd_card_set_dev
-#define snd_card_set_dev(card,devptr) ((card)->parent = (devptr))
+#define snd_card_set_dev(card,devptr) ((card)->dev = (devptr))
 #endif
 
 /* device.c */