[ALSA] hda-codec - Don't create vmaster if no slaves found

Don't create vmaster controls if no slaves are found in the given list.
This prevents the error due to an empty vmaster control.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 5c6419ead015..37c413923db8 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1055,6 +1055,12 @@ int snd_hda_add_vmaster(struct hda_codec *codec, char *name,
         const char **s;
         int err;
 
+        for (s = slaves; *s && !snd_hda_find_mixer_ctl(codec, *s); s++)
+                ;
+        if (!*s) {
+                snd_printdd("No slave found for %s\n", name);
+                return 0;
+        }
         kctl = snd_ctl_make_virtual_master(name, tlv);
         if (!kctl)
                 return -ENOMEM;