I ran into a small problem. I'm currently working on an application using the ESP Ethernet MAC. Everything works as expected.
The problem starts when no Ethernet cable is connected. After some minutes, I get the error message "emac_esp32_transmit(): insufficient TX buffer size". It seems like the IP-Stack tries sending packets without an established link. So the packets are queued until the TX buffer is full.
Normally, I would expect that packets are first transmitted after a Link-Up-Event. With of curse hasn't occurred when no cable is connected.
Is there a way to prevent queuing packets in the TX buffer before the link is established?
P.S. im using IDF Version: 5.0.1
Here is my code:
Code: Select all
/**
* @brief Event handler for Ethernet events, stop HTTPD server on disconnect event
*/
static void eth_event_handler(void *arg, esp_event_base_t event_base,
int32_t event_id, void *event_data)
{
//httpd_handle_t* server = (httpd_handle_t*) arg;
switch (event_id) {
case ETHERNET_EVENT_CONNECTED:
ESP_LOGI(TAG, "Ethernet Link Up");
break;
case ETHERNET_EVENT_DISCONNECTED:
ESP_LOGI(TAG, "Ethernet Link Down");
if (server) {
ESP_LOGI(TAG, "Stopping webserver");
if (http_stop_server() == ESP_OK) {
server = NULL;
} else {
ESP_LOGE(TAG, "Failed to stop http server");
}
}
break;
case ETHERNET_EVENT_START:
ESP_LOGI(TAG, "Ethernet Started");
break;
case ETHERNET_EVENT_STOP:
ESP_LOGI(TAG, "Ethernet Stopped");
break;
default:
break;
}
}
/**
* @brief Event handler for IP_EVENT_ETH_GOT_IP, start HTTPD server
*/
static void got_ip_event_handler(void *arg, esp_event_base_t event_base,
int32_t event_id, void *event_data)
{
if (server == NULL) {
ESP_LOGI(TAG, "Starting webserver");
if(http_start_server() == ESP_OK)
{
register_uris();
}
}
}
esp_err_t mdns_init_internal(char* hostname)
{
ESP_RETURN_ON_ERROR(mdns_init(), TAG, "initialize mDNS server failed");
ESP_RETURN_ON_ERROR(mdns_hostname_set(hostname), TAG, "setting hostname failed");
ESP_RETURN_ON_ERROR(mdns_instance_name_set(hostname), TAG, "setting instance name failed");
return ESP_OK;
}
/**
* @brief Internal ESP32 Ethernet initialization
*
* @return
* - esp_eth_handle_t if init succeeded
* - NULL if init failed
*/
static esp_eth_handle_t eth_init_internal(void)
{
esp_eth_handle_t ret = NULL;
// Init common MAC and PHY configs to default
eth_mac_config_t mac_config = ETH_MAC_DEFAULT_CONFIG();
eth_phy_config_t phy_config = ETH_PHY_DEFAULT_CONFIG();
// Update PHY config based on board specific configuration
phy_config.phy_addr = CONFIG_ETH_PHY_ADDR;
phy_config.reset_gpio_num = -1;
// Init vendor specific MAC config to default
eth_esp32_emac_config_t esp32_emac_config = ETH_ESP32_EMAC_DEFAULT_CONFIG();
// Update vendor specific MAC config based on board configuration
esp32_emac_config.smi_mdc_gpio_num = CONFIG_ETH_MDC_GPIO;
esp32_emac_config.smi_mdio_gpio_num = CONFIG_ETH_MDIO_GPIO;
// Create new ESP32 Ethernet MAC instance
esp_eth_mac_t *mac = esp_eth_mac_new_esp32(&esp32_emac_config, &mac_config);
// Create new PHY instance based on board configuration
esp_eth_phy_t *phy = esp_eth_phy_new_ksz8081(&phy_config);
// Init Ethernet driver to default and install it
esp_eth_handle_t eth_handle = NULL;
esp_eth_config_t config = ETH_DEFAULT_CONFIG(mac, phy);
ESP_GOTO_ON_FALSE(esp_eth_driver_install(&config, ð_handle) == ESP_OK, NULL, err, TAG, "Ethernet driver install failed");
return eth_handle;
err:
if (eth_handle != NULL) {
esp_eth_driver_uninstall(eth_handle);
}
if (mac != NULL) {
mac->del(mac);
}
if (phy != NULL) {
phy->del(phy);
}
return ret;
}
/**
* @brief Ethernet and HTTPD server initialization
*
* @return
* - ESP_OK if init succeeded
* - ESP_FAIL if not
*/
esp_err_t eth_init(char* hostname)
{
gpio_reset_pin(CONFIG_ETH_PHY_RST_GPIO);
gpio_set_direction(CONFIG_ETH_PHY_RST_GPIO, GPIO_MODE_OUTPUT);
gpio_set_level(CONFIG_ETH_PHY_RST_GPIO, 1); // Disable PHY reset, enable 50 MHz oszillator
vTaskDelay(10 / portTICK_PERIOD_MS); // Wait 10 ms for PHY to start up
// Initialize Ethernet driver
esp_eth_handle_t eth_handle = eth_init_internal();
ESP_RETURN_ON_FALSE(eth_handle, ESP_FAIL, TAG, "internal Ethernet init failed");
// Initialize TCP/IP network interface aka the esp-netif (should be called only once in application)
ESP_RETURN_ON_ERROR(esp_netif_init(), TAG, "TCP/IP network interface failed");
// Initialize mDNS server
ESP_RETURN_ON_ERROR(mdns_init_internal(hostname), TAG, "initialize mDNS server failed");
// Create instance of esp-netif for Ethernet with default esp-netif configuration parameters.
esp_netif_config_t cfg = ESP_NETIF_DEFAULT_ETH();
esp_netif_t *eth_netif = esp_netif_new(&cfg);
// Set device hostname for DHCP
ESP_RETURN_ON_ERROR(esp_netif_set_hostname(eth_netif, hostname), TAG, "setting hostname failed");
// Attach Ethernet driver to TCP/IP stack
ESP_RETURN_ON_ERROR(esp_netif_attach(eth_netif, esp_eth_new_netif_glue(eth_handle)), TAG, "attaching Ethernet driver to ip stack failed");
// Register user defined event handers
ESP_RETURN_ON_ERROR(esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, ð_event_handler, &server), TAG, "creating Ethernet event handler failed");
ESP_RETURN_ON_ERROR(esp_event_handler_register(IP_EVENT, IP_EVENT_ETH_GOT_IP, &got_ip_event_handler, &server), TAG, "creating IP event handler failed");
// Start Ethernet driver state machine
ESP_RETURN_ON_ERROR(esp_eth_start(eth_handle), TAG, "starting ethernet state machine failed");
return ESP_OK;
}