fix(uart): correct uart_get_tx_buffer_free_size calculation

Modified a bit on the TX ring buffer push size logic Closes https://github.com/espressif/esp-idf/issues/15859
2025-10-17 16:09:26 +08:00
parent fb20e147d5
commit 9629b2fb6a
3 changed files with 158 additions and 30 deletions
@@ -605,7 +605,9 @@ esp_err_t uart_flush_input(uart_port_t uart_num);
 esp_err_t uart_get_buffered_data_len(uart_port_t uart_num, size_t* size);

 /**
- * @brief   UART get TX ring buffer free space size
+ * @brief   UART get TX ring buffer free space size for the next data to be enqueued
+ *
+ * It returns the tight conservative bound for NOSPLIT ring buffer overall enqueueable payload across up to two chunks.
 *
 * @param   uart_num UART port number, the max port number is (UART_NUM_MAX -1).
 * @param   size Pointer of size_t to accept the free space size