[ALSA] Add error messages

Add error messages in the critial error path to be more verbose.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/sound/core/control.c b/sound/core/control.c
index 03ae9bb7d38e..f8f98cc52417 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -195,8 +195,10 @@ struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control, unsigned int acce
         snd_assert(control != NULL, return NULL);
         snd_assert(control->count > 0, return NULL);
         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
-        if (kctl == NULL)
+        if (kctl == NULL) {
+                snd_printk(KERN_ERR "Cannot allocate control instance\n");
                 return NULL;
+        }
         *kctl = *control;
         for (idx = 0; idx < kctl->count; idx++)
                 kctl->vd[idx].access = access;
@@ -309,7 +311,9 @@ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
         struct snd_ctl_elem_id id;
         unsigned int idx;
 
-        snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
+        snd_assert(card != NULL, return -EINVAL);
+        if (! kcontrol)
+                return -EINVAL;
         snd_assert(kcontrol->info != NULL, return -EINVAL);
         id = kcontrol->id;
         down_write(&card->controls_rwsem);