amr_mailbox_ioctl
mb_channel = ((struct amr_mailbox_ioctl *)&ac->ac_mailbox)->mb_channel;
((struct amr_mailbox_ioctl *)&ac->ac_mailbox)->mb_param = ac->ac_nsegments;
mb_channel = ((struct amr_mailbox_ioctl *)&ac->ac_mailbox)->mb_channel;
((struct amr_mailbox_ioctl *)&ac->ac_mailbox)->mb_param = ac->ac_nsegments;
struct amr_mailbox_ioctl *mbi;
mbi = (struct amr_mailbox_ioctl *)&ac->ac_mailbox;