ALSA: hda - Don't check capture source mixer if no ADC is available

With multiple codec configurations, some codec might have no ADC, thus
it keeps spec->adc_nids = NULL.  This causes an Oops in alc_build_controls().

Reference: kernel bug #16156
	https://bugzilla.kernel.org/show_bug.cgi?id=16156

Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 12 insertions, 10 deletions

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index fc767b6b4785..f6cd8ed3272f 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -2619,16 +2619,18 @@ static int alc_build_controls(struct hda_codec *codec)
         }
 
         /* assign Capture Source enums to NID */
-        kctl = snd_hda_find_mixer_ctl(codec, "Capture Source");
-        if (!kctl)
-                kctl = snd_hda_find_mixer_ctl(codec, "Input Source");
-        for (i = 0; kctl && i < kctl->count; i++) {
-                hda_nid_t *nids = spec->capsrc_nids;
-                if (!nids)
-                        nids = spec->adc_nids;
-                err = snd_hda_add_nid(codec, kctl, i, nids[i]);
-                if (err < 0)
-                        return err;
+        if (spec->capsrc_nids || spec->adc_nids) {
+                kctl = snd_hda_find_mixer_ctl(codec, "Capture Source");
+                if (!kctl)
+                        kctl = snd_hda_find_mixer_ctl(codec, "Input Source");
+                for (i = 0; kctl && i < kctl->count; i++) {
+                        hda_nid_t *nids = spec->capsrc_nids;
+                        if (!nids)
+                                nids = spec->adc_nids;
+                        err = snd_hda_add_nid(codec, kctl, i, nids[i]);
+                        if (err < 0)
+                                return err;
+                }
         }
         if (spec->cap_mixer) {
                 const char *kname = kctl ? kctl->id.name : NULL;