docs(ble): Revised the explanation for esp_bt_mem_release and esp_bt_controller_mem_release

Author: weiyuhannnn

components/bt/include/esp32/include/esp_bt.h

@@ -472,11 +472,11 @@ typedef struct esp_vhci_host_callback {
 /**
  * @brief Check whether the Controller is ready to receive the packet
  *
- *  If the return value is True, the Host can send the packet to the Controller.
+ *If the return value is True, the Host can send the packet to the Controller.
  *
- *  @note This function should be called before each `esp_vhci_host_send_packet()`.
+ *@note This function should be called before each `esp_vhci_host_send_packet()`.
  *
- *  @return
+ *@return
  *       True if the Controller is ready to receive packets; false otherwise
  */
 bool esp_vhci_host_check_send_available(void);
@@ -509,17 +509,17 @@ esp_err_t esp_vhci_host_register_callback(const esp_vhci_host_callback_t *callba
  *
  * This function releases the BSS, data and other sections of the Controller to heap. The total size is about 70 KB.
  *
- * If the app calls `esp_bt_controller_enable(ESP_BT_MODE_BLE)` to use BLE only,
- * then it is safe to call `esp_bt_controller_mem_release(ESP_BT_MODE_CLASSIC_BT)` at initialization time to free unused Classic Bluetooth memory.
+ * @note
+ *    1. This function is optional and should be called only if you want to free up memory for other components.
+ *    2. This function should only be called when the controller is in `ESP_BT_CONTROLLER_STATUS_IDLE` status.
+ *    3. Once Bluetooth Controller memory is released, the process cannot be reversed. This means you cannot use the Bluetooth Controller mode that you have released using this function.
+ *    4. If your firmware will upgrade the Bluetooth Controller mode later (such as switching from BLE to Classic Bluetooth or from disabled to enabled), then do not call this function.
  *
- * If the mode is `ESP_BT_MODE_BTDM`, then it may be useful to call API `esp_bt_mem_release(ESP_BT_MODE_BTDM)` instead,
- * which internally calls `esp_bt_controller_mem_release(ESP_BT_MODE_BTDM)` and additionally releases the BSS and data
- * consumed by the Classic Bluetooth/BLE Host stack to heap. For more details about usage please refer to the documentation of `esp_bt_mem_release()` function.
+ * If you never intend to use Bluetooth in a current boot-up cycle, calling `esp_bt_controller_mem_release(ESP_BT_MODE_BTDM)` could release the BSS and data consumed by both Classic Bluetooth and BLE Controller to heap.
  *
- * @note
- *      1. This function should be called only before `esp_bt_controller_init()` or after `esp_bt_controller_deinit()`.
- *      2. Once Bluetooth Controller memory is released, the process cannot be reversed. This means you cannot use the Bluetooth Controller mode that you have released using this function.
- *      3. If your firmware will upgrade the Bluetooth Controller mode later (such as switching from BLE to Classic Bluetooth or from disabled to enabled), then do not call this function.
+ * If you intend to use BLE only, calling `esp_bt_controller_mem_release(ESP_BT_MODE_CLASSIC_BT)` could release the BSS and data consumed by Classic Bluetooth Controller. You can then continue using BLE.
+ *
+ * If you intend to use Classic Bluetooth only, calling `esp_bt_controller_mem_release(ESP_BT_MODE_BLE)` could release the BSS and data consumed by BLE Controller. You can then continue using Classic Bluetooth.
  *
  * @param[in] mode The Bluetooth Controller mode
  *
@@ -530,13 +530,22 @@ esp_err_t esp_vhci_host_register_callback(const esp_vhci_host_callback_t *callba
  */
 esp_err_t esp_bt_controller_mem_release(esp_bt_mode_t mode);
 
-/** @brief Release the Controller memory, BSS and data section of the Classic Bluetooth/BLE Host stack as per the mode
+/** 
+ * @brief Release the Controller memory, BSS and data section of the Classic Bluetooth/BLE Host stack as per the mode
+ *
+ * @note
+ *    1. This function is optional and should be called only if you want to free up memory for other components.
+ *    2. This function should only be called when the controller is in `ESP_BT_CONTROLLER_STATUS_IDLE` status.
+ *    3. Once Bluetooth Controller memory is released, the process cannot be reversed. This means you cannot use the Bluetooth Controller mode that you have released using this function.
+ *    4. If your firmware will upgrade the Bluetooth Controller mode later (such as switching from BLE to Classic Bluetooth or from disabled to enabled), then do not call this function.
  *
- * This function first releases Controller memory by internally calling `esp_bt_controller_mem_release()`.
- * Additionally, if the mode is set to `ESP_BT_MODE_BTDM`, it also releases the BSS and data consumed by the Classic Bluetooth and BLE Host stack to heap.
+ * This function first releases Controller memory by internally calling `esp_bt_controller_mem_release()`, then releases Host memory.
  *
- * If you never intend to use Bluetooth in a current boot-up cycle, you can call `esp_bt_mem_release(ESP_BT_MODE_BTDM)`
- * before `esp_bt_controller_init()` or after `esp_bt_controller_deinit()`.
+ * If you never intend to use Bluetooth in a current boot-up cycle, calling `esp_bt_mem_release(ESP_BT_MODE_BTDM)` could release the BSS and data consumed by both Classic Bluetooth and BLE stack to heap.
+ *
+ * If you intend to use BLE only, calling `esp_bt_mem_release(ESP_BT_MODE_CLASSIC_BT)` could release the BSS and data consumed by Classic Bluetooth. You can then continue using BLE.
+ *
+ * If you intend to use Classic Bluetooth only, calling `esp_bt_mem_release(ESP_BT_MODE_BLE)` could release the BSS and data consumed by BLE. You can then continue using Classic Bluetooth.
  *
  * For example, if you only use Bluetooth for setting the Wi-Fi configuration, and do not use Bluetooth in the rest of the product operation,
  *  after receiving the Wi-Fi configuration, you can disable/de-init Bluetooth and release its memory.
@@ -548,11 +557,6 @@ esp_err_t esp_bt_controller_mem_release(esp_bt_mode_t mode);
  *       esp_bt_controller_deinit();
  *       esp_bt_mem_release(ESP_BT_MODE_BTDM);
  *
- * @note
- *    1.  Once Bluetooth Controller memory is released, the process cannot be reversed. This means you cannot use the Bluetooth Controller mode that you have released using this function.
- *    2.  If your firmware will upgrade the Bluetooth Controller mode later (such as switching from BLE to Classic Bluetooth or from disabled to enabled), then do not call this function.
- *    3.  In case of NimBLE Host, to release BSS and data memory to heap, the mode needs to be set to `ESP_BT_MODE_BTDM` as the Controller is in Dual mode.
- *
  * @param[in] mode The Bluetooth Controller mode
  *
  * @return