@@ -1943,10 +1943,6 @@ static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termio
rs485conf->flags & SER_RS485_RX_DURING_TX)
imx_uart_start_rx(port);
- if (port->rs485_rx_during_tx_gpio)
- gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
- !!(rs485conf->flags & SER_RS485_RX_DURING_TX));
-
return 0;
}
@@ -1392,14 +1392,21 @@ static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs4
memset(rs485->padding1, 0, sizeof(rs485->padding1));
}
-static void uart_set_rs485_termination(struct uart_port *port,
- const struct serial_rs485 *rs485)
+/*
+ * Set optional RS485 GPIOs for bus termination and data reception during
+ * transmission. These GPIOs are controlled by the serial core independently
+ * from the UART driver.
+ */
+static void uart_set_rs485_gpios(struct uart_port *port,
+ const struct serial_rs485 *rs485)
{
if (!(rs485->flags & SER_RS485_ENABLED))
return;
gpiod_set_value_cansleep(port->rs485_term_gpio,
!!(rs485->flags & SER_RS485_TERMINATE_BUS));
+ gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
+ !!(rs485->flags & SER_RS485_RX_DURING_TX));
}
static int uart_rs485_config(struct uart_port *port)
@@ -1412,7 +1419,7 @@ static int uart_rs485_config(struct uart_port *port)
return 0;
uart_sanitize_serial_rs485(port, rs485);
- uart_set_rs485_termination(port, rs485);
+ uart_set_rs485_gpios(port, rs485);
uart_port_lock_irqsave(port, &flags);
ret = port->rs485_config(port, NULL, rs485);
@@ -1456,7 +1463,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
if (ret)
return ret;
uart_sanitize_serial_rs485(port, &rs485);
- uart_set_rs485_termination(port, &rs485);
+ uart_set_rs485_gpios(port, &rs485);
uart_port_lock_irqsave(port, &flags);
ret = port->rs485_config(port, &tty->termios, &rs485);
@@ -226,10 +226,7 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
- if (port->rs485_rx_during_tx_gpio)
- gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
- !!(rs485conf->flags & SER_RS485_RX_DURING_TX));
- else
+ if (!port->rs485_rx_during_tx_gpio)
rs485conf->flags |= SER_RS485_RX_DURING_TX;
if (rs485conf->flags & SER_RS485_ENABLED) {
Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config(). Since this function is called with the port lock held, this can be an problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Since both setting the term and the rx-during-tx GPIO is done at the same code place, move it into a common function. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> --- drivers/tty/serial/imx.c | 4 ---- drivers/tty/serial/serial_core.c | 15 +++++++++++---- drivers/tty/serial/stm32-usart.c | 5 +---- 3 files changed, 12 insertions(+), 12 deletions(-)