| Message ID | 20160912094733.21501-3-richard.genoud@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Sep 12, 2016 at 11:47:32AM +0200, Richard Genoud wrote: > Commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when > hardware handshake is enabled") broke the hardware handshake when GPIOs > where 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. > > This commit restores this behaviour. > > NB: -stable is not Cced because it doesn't cleanly apply on 4.1+ > and it will also need previous commit: > "serial: mctrl_gpio: implement mctrl_gpio_use_rtscts" > > Signed-off-by: Richard Genoud <richard.genoud@gmail.com> > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") > --- > drivers/tty/serial/atmel_serial.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) This patch doesn't apply to my tree, are you sure it's up to date? Can you please refresh this whole series against linux-next and resend? thanks, greg k-h
On Mon, Sep 12, 2016 at 11:47:32AM +0200, Richard Genoud wrote: > Commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when > hardware handshake is enabled") broke the hardware handshake when GPIOs > where used. s/where/were/ > 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. > > This commit restores this behaviour. > > NB: -stable is not Cced because it doesn't cleanly apply on 4.1+ > and it will also need previous commit: > "serial: mctrl_gpio: implement mctrl_gpio_use_rtscts" > > Signed-off-by: Richard Genoud <richard.genoud@gmail.com> > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") > --- > drivers/tty/serial/atmel_serial.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index 2eaa18ddef61..e9b4fbf88c2d 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -2025,6 +2025,7 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state, > static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > struct ktermios *old) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > unsigned long flags; > unsigned int old_mode, mode, imr, quot, baud; > > @@ -2126,8 +2127,12 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > atmel_uart_writel(port, ATMEL_US_TTGR, > port->rs485.delay_rts_after_send); > mode |= ATMEL_US_USMODE_RS485; > - } else if (termios->c_cflag & CRTSCTS) { > - /* RS232 with hardware handshake (RTS/CTS) */ > + } else if ((termios->c_cflag & CRTSCTS) && > + !mctrl_gpio_use_rtscts(atmel_port->gpios)) { IMHO the behaviour of the hw controlled pins shouldn't change when mctrl_gpio is in use (if possible). But I don't understand the issue so I guess you need a better changelog. > + /* > + * RS232 with hardware handshake (RTS/CTS) > + * handled by the controller. > + */ > if (atmel_use_dma_rx(port) && !atmel_use_fifo(port)) { > dev_info(port->dev, "not enabling hardware flow control because DMA is used"); > termios->c_cflag &= ~CRTSCTS; > @@ -2135,7 +2140,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > mode |= ATMEL_US_USMODE_HWHS; > } > } else { > - /* RS232 without hadware handshake */ > + /* RS232 without hadware handshake or controlled by GPIOs */ When touching this line, please also do s/hadware/hardware/. > mode |= ATMEL_US_USMODE_NORMAL; > } Best regards Uwe
2016-09-22 15:20 GMT+02:00 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>: > On Mon, Sep 12, 2016 at 11:47:32AM +0200, Richard Genoud wrote: >> Commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when >> hardware handshake is enabled") broke the hardware handshake when GPIOs >> where used. > > s/where/were/ ok. >> 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. >> >> This commit restores this behaviour. >> >> NB: -stable is not Cced because it doesn't cleanly apply on 4.1+ >> and it will also need previous commit: >> "serial: mctrl_gpio: implement mctrl_gpio_use_rtscts" >> >> Signed-off-by: Richard Genoud <richard.genoud@gmail.com> >> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> >> Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") >> --- >> drivers/tty/serial/atmel_serial.c | 11 ++++++++--- >> 1 file changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c >> index 2eaa18ddef61..e9b4fbf88c2d 100644 >> --- a/drivers/tty/serial/atmel_serial.c >> +++ b/drivers/tty/serial/atmel_serial.c >> @@ -2025,6 +2025,7 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state, >> static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, >> struct ktermios *old) >> { >> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); >> unsigned long flags; >> unsigned int old_mode, mode, imr, quot, baud; >> >> @@ -2126,8 +2127,12 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, >> atmel_uart_writel(port, ATMEL_US_TTGR, >> port->rs485.delay_rts_after_send); >> mode |= ATMEL_US_USMODE_RS485; >> - } else if (termios->c_cflag & CRTSCTS) { >> - /* RS232 with hardware handshake (RTS/CTS) */ >> + } else if ((termios->c_cflag & CRTSCTS) && >> + !mctrl_gpio_use_rtscts(atmel_port->gpios)) { > > IMHO the behaviour of the hw controlled pins shouldn't change when > mctrl_gpio is in use (if possible). But I don't understand the issue so > I guess you need a better changelog. Yes, the behavior of the CTS/RTS pins should the same whenever they are GPIOs or not. That was the case before commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") BUT, this commit (1cf6e8fc834) introduced the actual use of the ATMEL_US_USMODE_HWHS flag. This flags changes the way RTS/CTS pins are driven, and that's the discussion we are having in patch 3/3. >> + /* >> + * RS232 with hardware handshake (RTS/CTS) >> + * handled by the controller. >> + */ >> if (atmel_use_dma_rx(port) && !atmel_use_fifo(port)) { >> dev_info(port->dev, "not enabling hardware flow control because DMA is used"); >> termios->c_cflag &= ~CRTSCTS; >> @@ -2135,7 +2140,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, >> mode |= ATMEL_US_USMODE_HWHS; >> } >> } else { >> - /* RS232 without hadware handshake */ >> + /* RS232 without hadware handshake or controlled by GPIOs */ > > When touching this line, please also do s/hadware/hardware/. ok. > >> mode |= ATMEL_US_USMODE_NORMAL; >> } > > Best regards > Uwe Thanks.
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 2eaa18ddef61..e9b4fbf88c2d 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2025,6 +2025,7 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state, static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned long flags; unsigned int old_mode, mode, imr, quot, baud; @@ -2126,8 +2127,12 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, atmel_uart_writel(port, ATMEL_US_TTGR, port->rs485.delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; - } else if (termios->c_cflag & CRTSCTS) { - /* RS232 with hardware handshake (RTS/CTS) */ + } else if ((termios->c_cflag & CRTSCTS) && + !mctrl_gpio_use_rtscts(atmel_port->gpios)) { + /* + * RS232 with hardware handshake (RTS/CTS) + * handled by the controller. + */ if (atmel_use_dma_rx(port) && !atmel_use_fifo(port)) { dev_info(port->dev, "not enabling hardware flow control because DMA is used"); termios->c_cflag &= ~CRTSCTS; @@ -2135,7 +2140,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, mode |= ATMEL_US_USMODE_HWHS; } } else { - /* RS232 without hadware handshake */ + /* RS232 without hadware handshake or controlled by GPIOs */ mode |= ATMEL_US_USMODE_NORMAL; }
Commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") broke the hardware handshake when GPIOs where 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. This commit restores this behaviour. NB: -stable is not Cced because it doesn't cleanly apply on 4.1+ and it will also need previous commit: "serial: mctrl_gpio: implement mctrl_gpio_use_rtscts" Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") --- drivers/tty/serial/atmel_serial.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)