It am using QN9021 SoC working in controller mode (BLE Bluetooth core specification v4.0). It supports some standard HCI commands as well as some vendor specific commands. I am trying to attach it in my ubuntu laptop.
The command that i have used is
hciattach -s 9600 /dev/ttyUSBx any 9600 noflow nosleep
The hcidump shows while executing sudo hciconfig hci1 up.
HCI sniffer - Bluetooth packet analyzer ver 5.37 device: hci1 snap_len: 1500 filter: 0xffffffffffffffff > HCI Event: Command Complete (0x0e) plen 12 Read Local Supported Features (0x04|0x0003) ncmd 11 status 0x00 Features: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 > HCI Event: Command Complete (0x0e) plen 12 Read Local Version Information (0x04|0x0001) ncmd 11 status 0x00 HCI Version: 4.0 (0x6) HCI Revision: 0x400 LMP Version: 4.0 (0x6) LMP Subversion: 0x400 Manufacturer: Quintic Corp. (142) > HCI Event: Command Complete (0x0e) plen 10 Read BD ADDR (0x04|0x0009) ncmd 11 status 0x00 bdaddr 08:7C:BE:3E:34:BB > HCI Event: Command Complete (0x0e) plen 11 Read Buffer Size (0x04|0x0005) ncmd 11 status 0x00 ACL MTU 0:0 SCO MTU 0:0 > HCI Event: Command Complete (0x0e) plen 4 Read Class of Device (0x03|0x0023) ncmd 11 status 0x01 class 0x000000 Error: Unknown HCI Command
The hciconfig command shows:
hci1: Type: BR/EDR Bus: UART BD Address: 08:7C:BE:3E:34:BB ACL MTU: 0:0 SCO MTU: 0:0 DOWN RX bytes:192 acl:0 sco:0 events:15 errors:0 TX bytes:60 acl:0 sco:0 commands:15 errors:0 hci0: Type: BR/EDR Bus: USB BD Address: C4:8E:8F:66:3B:0E ACL MTU: 820:8 SCO MTU: 255:16 UP RUNNING PSCAN RX bytes:2457 acl:0 sco:0 events:196 errors:0 TX bytes:24646 acl:0 sco:0 commands:196 errors:0
I would like to know how to prevent the kernel or some bluetooth kernel module to send non-supported HCI commands. Do i need to patch linux kernel source code or write a module for my SoC.
Note:- Changing the SoC or writing firmware for it to support all necessary commands is not possible for this project.
I know the list of HCIcommand supported by my SoC. I am thinking of creating a module to tell the kernel and daemons running to send only supported commands to the SoC. I have a look at linux kernel source (specifically at this hci_core.c). I think modifying it may solve the problem after going through this link. In this link, some developer has provided a patch to support a bluetooth dongle. The patch prevents the hci_core.c file to send a specific HCI command to a dongle of a particular manufacturer.
All i want is suggestion to resolve this problem. Do i need to modify the linux kernel or write a module for my SoC?
NOTE:- The application will run on openwrt linux.