USART_SR_DUMMY_RX  228 drivers/tty/serial/stm32-usart.c 		sr |= USART_SR_DUMMY_RX;
USART_SR_DUMMY_RX  817 drivers/tty/serial/stm32-usart.c 		port->ignore_status_mask |= USART_SR_DUMMY_RX;