esp_wifi: optimize WiFi TX performance

components/esp_wifi/src/wifi_default.c

@@ -58,6 +58,10 @@ static void wifi_start(void *esp_netif, esp_event_base_t base, int32_t event_id,
         }
     }
 
+    if ((ret = esp_wifi_internal_reg_netstack_buf_cb(esp_netif_netstack_buf_ref, esp_netif_netstack_buf_free)) != ESP_OK) {
+        ESP_LOGE(TAG, "netstack cb reg failed with %d", ret);
+        return;
+    }
     esp_netif_set_mac(esp_netif, mac);
     esp_netif_action_start(esp_netif, base, event_id, data);
 }

components/esp_wifi/src/wifi_init.c

@@ -50,6 +50,9 @@ uint64_t g_wifi_feature_caps =
 #if CONFIG_ESP32_WIFI_ENABLE_WPA3_SAE
     CONFIG_FEATURE_WPA3_SAE_BIT |
 #endif
+#if (CONFIG_ESP32_SPIRAM_SUPPORT | CONFIG_ESP32S2_SPIRAM_SUPPORT)
+    CONFIG_FEATURE_CACHE_TX_BUF_BIT |
+#endif
 0;
 
 static const char* TAG = "wifi_init";

components/esp_wifi/src/wifi_netif.c

@@ -63,6 +63,16 @@ static esp_err_t wifi_transmit(void *h, void *buffer, size_t len)
     return esp_wifi_internal_tx(driver->wifi_if, buffer, len);
 }
 
+static esp_err_t wifi_transmit_wrap(void *h, void *buffer, size_t len, void *netstack_buf)
+{
+    wifi_netif_driver_t driver = h;
+#if (CONFIG_ESP32_SPIRAM_SUPPORT | CONFIG_ESP32S2_SPIRAM_SUPPORT)
+    return esp_wifi_internal_tx_by_ref(driver->wifi_if, buffer, len, netstack_buf);
+#else
+    return esp_wifi_internal_tx(driver->wifi_if, buffer, len);
+#endif
+}
+
 static esp_err_t wifi_driver_start(esp_netif_t * esp_netif, void * args)
 {
     wifi_netif_driver_t driver = args;
@@ -70,6 +80,7 @@ static esp_err_t wifi_driver_start(esp_netif_t * esp_netif, void * args)
     esp_netif_driver_ifconfig_t driver_ifconfig = {
             .handle =  driver,
             .transmit = wifi_transmit,
+            .transmit_wrap= wifi_transmit_wrap,
             .driver_free_rx_buffer = wifi_free
     };