USART_CR3_RXFTIE  714 drivers/tty/serial/stm32-usart.c 	cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE
USART_CR3_RXFTIE  756 drivers/tty/serial/stm32-usart.c 			stm32_port->cr3_irq =  USART_CR3_RXFTIE;