Hi Karol,
Actually, I have tried different combinations like framework or driver, DTC or not. However, I can't figure out a single way to do it. No matter I use DTC or not, my callback function is still invoked with event UART_EVENT_RX_CHAR. As I mentioned before, without DTC, g_uart1.p_api->read is dummy code. With DTC, the g_uart1.p_api->read waits for new input and cannot pop out bytes received previously through p_args->data. In both cases, UART_EVENT_ERR_OVERFLOW cannot be avoided.