ESP32 BLE threads causing extremely slow TLS computation over WiFi

[arifbalik]

I am working with esp32 (esp32-wroom-32-n4) with BLE and Wifi enabled at the same time, and also connecting to an mqtt broker via secure ports.

A standalone application that just connects to BLE and mqtt broker works fine, but whenever I try to create a thread (with lowest preemtive prio) to pull and process the data from these channels the mqtt connection fails becuase the TLS handshake is extremely slow (~30 seconds on avarage) and even after the connection is made the messages arrives way too late.

When I analyze the thread utilization I dont neccesarily see the BT threads starving other threads but whenever I disable BT subsys, everything works just fine. And BT threads have the highest priority (all coopertive threads), maybe interrupts causing this?

I have the following configuration;

# Network Config
CONFIG_NETWORKING=y
CONFIG_NET_IPV6=n
CONFIG_NET_IPV4=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_TCP=y
CONFIG_NET_CONFIG_SETTINGS=y
CONFIG_NET_SOCKETS_SOCKOPT_TLS=y
CONFIG_NET_HOSTNAME_ENABLE=y
CONFIG_NET_HOSTNAME="enda_iot1_appwifi"

# MQTT Config
CONFIG_MQTT_LIB=y
CONFIG_MQTT_LIB_TLS=y
CONFIG_ENDA_MQTT_KEEPALIVE_SECONDS=30
CONFIG_ENDA_MQTT=y

# DNS Config
CONFIG_DNS_RESOLVER=y
CONFIG_DNS_SERVER_IP_ADDRESSES=y
CONFIG_DNS_SERVER1="8.8.8.8"

# mbedTLS Config
CONFIG_MBEDTLS=y
CONFIG_MBEDTLS_BUILTIN=y
CONFIG_MBEDTLS_SSL_MAX_CONTENT_LEN=2048
CONFIG_MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED=y
CONFIG_MBEDTLS_ECDH_C=y
CONFIG_MBEDTLS_ECDSA_C=y
CONFIG_MBEDTLS_ECP_C=y
CONFIG_MBEDTLS_ECP_DP_SECP256R1_ENABLED=y
CONFIG_MBEDTLS_HMAC_DRBG_ENABLED=y
# PSA
CONFIG_MBEDTLS_PSA_CRYPTO_C=y
CONFIG_MBEDTLS_USE_PSA_CRYPTO=y
CONFIG_PSA_CRYPTO_ENABLE_ALL=y

# Logging
CONFIG_LOG=y
CONFIG_LOG_MODE_IMMEDIATE=y
CONFIG_NET_LOG=n
CONFIG_EVENTS=y

# Entropy
CONFIG_ENTROPY_GENERATOR=y
CONFIG_MBEDTLS_ZEPHYR_ENTROPY=y

# Memory
CONFIG_MAIN_STACK_SIZE=8192
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=8192
CONFIG_NET_SOCKETS_SERVICE_STACK_SIZE=4096
CONFIG_ISR_STACK_SIZE=4096
CONFIG_INIT_STACKS=y

# Nanopb
CONFIG_NANOPB=y
CONFIG_ENDA_NANOPB=y

# Bluetooth
CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_NAME_DYNAMIC=y
CONFIG_BT_DIS=y
CONFIG_BT_GATT_CLIENT=y
CONFIG_BT_GATT_DYNAMIC_DB=y

# Settings
CONFIG_NVS=y
CONFIG_FLASH=y
CONFIG_FLASH_MAP=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_NVS=y

CONFIG_REBOOT=y
CONFIG_THREAD_NAME=y

# Modbus
CONFIG_MODBUS=y
CONFIG_MODBUS_LOG_LEVEL_ERR=y

# Flash
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y

# Network Config
CONFIG_NET_CONFIG_AUTO_INIT=n
CONFIG_NET_DHCPV4=y
CONFIG_NET_IF_MAX_IPV4_COUNT=2
CONFIG_NET_MGMT=y
CONFIG_NET_MGMT_EVENT=y
CONFIG_NET_L2_ETHERNET=y

# WiFi Config
CONFIG_WIFI=y
CONFIG_WIFI_ESP32=y
CONFIG_ESP32_WIFI_STA_AUTO_DHCPV4=y
CONFIG_ESP32_WIFI_STA_RECONNECT=y

# Misc
CONFIG_REQUIRES_FULL_LIBC=y
CONFIG_POSIX_API=y
CONFIG_POSIX_TIMERS=y