Hello Richard, On Fri, Sep 30, 2016 at 10:58:00AM +0200, Richard Genoud wrote: > Commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when > hardware handshake is enabled") broke the hardware handshake when GPIOs > were used. > > Hardware handshake with GPIOs used to work before this commit because > the CRTSCTS flag (termios->c_cflag) was set, but not the > ATMEL_US_USMODE_HWHS flag (controller register) ; so hardware handshake > enabled, but not handled by the controller. What does the HWHS flag control? What if only RTS is a gpio and CTS is not? Or the other way round? What is the problematic setup? I guess it's RTS and CTS are gpios and with that setting ATMEL_US_USMODE_HWHS is wrong? What happens if that happens? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html