Add the control instance to the card
int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
card
the card instance
kcontrol
the control instance to add
Adds the control instance created via snd_ctl_new or snd_ctl_new1 to the given card. Assigns also an unique numid used for fast search.
It frees automatically the control which cannot be added.
Zero if successful, or a negative error code on failure.