espressif ping: reduce wait time on failure^

Author: dhalbert

ports/espressif/common-hal/wifi/Radio.c

@@ -554,21 +554,18 @@ mp_int_t common_hal_wifi_radio_ping(wifi_radio_obj_t *self, mp_obj_t ip_address,
     // ESP-IDF creates a task to do the ping session. It shuts down when done, but only after a one second delay.
     // Calling common_hal_wifi_radio_ping() too fast will cause resource exhaustion.
     esp_ping_handle_t ping;
-    esp_err_t ret;
-    for (size_t tries = 1; tries <= 5; tries++) {
-        ret = esp_ping_new_session(&ping_config, &ping_callbacks, &ping);
-        if (ret == ESP_OK) {
-            break;
-        }
+    if (esp_ping_new_session(&ping_config, &ping_callbacks, &ping) != ESP_OK) {
         // Wait for old task to go away and then try again.
         // Empirical testing shows we have to wait at least two seconds, despite the task
         // having a one-second timeout.
         common_hal_time_delay_ms(2000);
+        // Return if interrupted now, to show the interruption as KeyboardInterrupt instead of the
+        // IDF error.
         if (mp_hal_is_interrupted()) {
-            return -1;
+            return (uint32_t)(-1);
         }
+        CHECK_ESP_RESULT(esp_ping_new_session(&ping_config, &ping_callbacks, &ping));
     }
-    CHECK_ESP_RESULT(ret);
 
     esp_ping_start(ping);
 

shared-bindings/wifi/Radio.c

@@ -698,7 +698,12 @@ MP_PROPERTY_GETTER(wifi_radio_ap_info_obj,
 //|         self, ip: ipaddress.IPv4Address, *, timeout: Optional[float] = 0.5
 //|     ) -> Optional[float]:
 //|         """Ping an IP to test connectivity. Returns echo time in seconds.
-//|         Returns None when it times out."""
+//|         Returns None when it times out.
+//|
+//|         **Limitations:** On Espressif, calling `ping()` multiple times rapidly
+//|         exhausts available resources after several calls. Rather than failing at that point, `ping()`
+//|         will wait two seconds for enough resources to be freed up before proceeding.
+//|         """
 //|         ...
 //|
 static mp_obj_t wifi_radio_ping(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {