블루투스 디버깅 관련 - Permission denied

"Can't connect RFCOMM socket: Permission denied"

블루투스 연결시 계속 이런 에러가 발생하였다.
여기저기 검색하였지만, 뾰족한 답을 얻을 수 없었다.
그러다가,
/etc/bluetooth/hcid.conf

이 파일을 수정해주었더니 정상 동작하였다.

#
# HCI daemon configuration file.
#

# HCId options
options {
        # Automatically initialize new devices
        autoinit yes;

        # Security Manager mode
        #   none - Security manager disabled
        #   auto - Use local PIN for incoming connections
        #   user - Always ask user for a PIN
        #
        security user;

        # Pairing mode
        #   none  - Pairing disabled
        #   multi - Allow pairing with already paired devices
        #   once  - Pair once and deny successive attempts
        pairing multi;

        # Default PIN code for incoming connections
                passkey "1234";
}

# Default settings for HCI devices
device {
        # Local device name
        #   %d - device id
        #   %h - host name
        name "%h-%d";

        # Local device class
        class 0x3e0100;

        # Default packet type
        #pkt_type DH1,DM1,HV1;

        # Inquiry and Page scan
        iscan enable; pscan enable;
        discovto 0;

        # Default link mode
        #   none   - no specific policy
        #   accept - always accept incoming connections
        #   master - become master on incoming connections,
        #            deny role switch on outgoing connections
        lm accept;

        # Default link policy
        #   none    - no specific policy
        #   rswitch - allow role switch
        #   hold    - allow hold mode
        #   sniff   - allow sniff mode
        #   park    - allow park mode
        lp rswitch,hold,sniff,park;
}