Hello Folks, I would like to Send Signed Write command to modify a characteristic on the Host. It failed into the Error: Failed to initiate write without response procedure Information on Controller (May be helpful): root@imx28evk:~# cat /proc/crypto name : ecb(aes) driver : ecb-aes-dcp module : kernel priority : 400 refcnt : 1 selftest : passed type : ablkcipher async : yes blocksize : 16 min keysize : 16 max keysize : 32 ivsize : 0 geniv : <default> root@imx28evk:~# btmgmt info Index list with 1 item hci0: Primary controller addr 1C:BA:8C:86:81:21 version 6 manufacturer 13 class 0x000000 supported settings: powered connectable fast-connectable discoverable bondable link-security ssp br/edr hs le advertising debug-keys privacy current settings: powered connectable discoverable bondable link-security br/edr le advertising name testbt short name root@imx28evk:~/tools# btgatt-client -d 00:1B:DC:07:2E:85 Connecting to device... Done Service Added - UUID: 00001800-0000-1000-8000-00805f9b34fb start: 0x0001 end: 0x000d Service Added - UUID: 00001801-0000-1000-8000-00805f9b34fb start: 0x0014 end: 0x0016 [GATT client]# GATT discovery procedures complete [GATT client]# ... [GATT client]# set-sign-key -c efcdab8967452301efcdab8967452301 [GATT client]# write-value -s -w 0xd 01 Failed to initiate write without response procedure I tried to trace the error as: bt_gatt_client_write_without_response(..) -> bt_att_send(..) -> create_att_send_op(..) -> encode_pdu(..) -> bt_crypto_sign_att(..) -> As att->crypto is NULL it returns false. I tried to check the reason for att->crypto to be NULL. Found that while initialization of the btgatt-client, under bt_crypto_new() -> crypto->ecb_aes = ecb_aes_setup();. It fails under ecb_aes_setup function. From the output of /proc/crypto, the kernel has the support. I am wondering how to enable the crypto? Regards, Ankur. -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html