AMR_CMD_BUSY
while ((ac->ac_flags & AMR_CMD_BUSY) && (error != EWOULDBLOCK)) {
} while ((ac->ac_flags & AMR_CMD_BUSY) && (count++ < 1000));
if (!(ac->ac_flags & AMR_CMD_BUSY)) {
ac->ac_flags |= AMR_CMD_BUSY;
ac->ac_flags &= ~AMR_CMD_BUSY;
ac->ac_flags &= ~AMR_CMD_BUSY;