WiFi: Disable 11b rates

802.11b has been obsolete for about 20 years. Keeping compatibility around
slows down devices not 20 years old.

Author: rtrbt

libraries/WiFi/src/WiFiGeneric.cpp

@@ -450,6 +450,7 @@ static bool espWiFiStop() {
 
 bool WiFiGenericClass::_persistent = true;
 bool WiFiGenericClass::_long_range = false;
+bool WiFiGenericClass::_disable_sta_11b = true;
 wifi_mode_t WiFiGenericClass::_forceSleepLastMode = WIFI_MODE_NULL;
 #if CONFIG_IDF_TARGET_ESP32S2
 wifi_ps_type_t WiFiGenericClass::_sleepEnabled = WIFI_PS_NONE;
@@ -563,6 +564,15 @@ void WiFiGenericClass::enableLongRange(bool enable) {
   _long_range = enable;
 }
 
+/**
+ * disable 11b rates
+ * @param disable
+ */
+void WiFiGenericClass::disableSTA11b(bool disable)
+{
+    _disable_sta_11b = disable;
+}
+
 /**
  * set new mode
  * @param m WiFiMode_t
@@ -672,6 +682,12 @@ bool WiFiGenericClass::mode(wifi_mode_t m) {
       }
     }
   }
+  // 11b is long obsolete. true = disable. Don't care if it can't be disabled.
+  // Disable both because neither can be changed when trying to switch mode later.
+  // Always disable 11b on AP because beacons are sent at minimum rate.
+  esp_wifi_config_11b_rate(WIFI_IF_STA, _disable_sta_11b);
+  esp_wifi_config_11b_rate(WIFI_IF_AP, true);
+
   if (!espWiFiStart()) {
     return false;
   }

libraries/WiFi/src/WiFiGeneric.h

@@ -102,6 +102,7 @@ class WiFiGenericClass {
 
   void persistent(bool persistent);
   void enableLongRange(bool enable);
+  void disableSTA11b(bool disable);
 
   static bool mode(wifi_mode_t);
   static wifi_mode_t getMode();
@@ -143,6 +144,7 @@ class WiFiGenericClass {
 protected:
   static bool _persistent;
   static bool _long_range;
+  static bool _disable_sta_11b;
   static wifi_mode_t _forceSleepLastMode;
   static wifi_ps_type_t _sleepEnabled;
   static bool _wifiUseStaticBuffers;