[PATCH] ALSA: core: Warn on empty module

[Takashi Iwai <tiwai@suse.de>]

The module argument passed to snd_card_new() must be a valid non-NULL
pointer when the module support is enabled.  Since ASoC driver passes
the argument from each snd_soc_card definition, one may forget to set
the owner field and lead to a NULL module easily.

For catching such an overlook, add a WARN_ON() in snd_card_new().
Also, put the card->module assignment in the ifdef block for a very
minor optimization.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/core/init.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/core/init.c b/sound/core/init.c
index b02a99766351..0478847ba2b8 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -203,7 +203,10 @@ int snd_card_new(struct device *parent, int idx, const char *xid,
 	mutex_unlock(&snd_card_mutex);
 	card->dev = parent;
 	card->number = idx;
+#ifdef MODULE
+	WARN_ON(!module);
 	card->module = module;
+#endif
 	INIT_LIST_HEAD(&card->devices);
 	init_rwsem(&card->controls_rwsem);
 	rwlock_init(&card->ctl_files_rwlock);
-- 
2.16.4