mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
serial: Do not hold the port lock when setting rx-during-tx GPIO
commit07c30ea586
upstream. 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 a 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. Also with commitc54d485436
("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes:c54d485436
("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes:ca530cfa96
("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> Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
26c3817cc8
commit
90b8cbd90a
3 changed files with 26 additions and 12 deletions
|
@ -1947,10 +1947,6 @@ 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;
|
||||
}
|
||||
|
||||
|
|
|
@ -1409,6 +1409,16 @@ static void uart_set_rs485_termination(struct uart_port *port,
|
|||
!!(rs485->flags & SER_RS485_TERMINATE_BUS));
|
||||
}
|
||||
|
||||
static void uart_set_rs485_rx_during_tx(struct uart_port *port,
|
||||
const struct serial_rs485 *rs485)
|
||||
{
|
||||
if (!(rs485->flags & SER_RS485_ENABLED))
|
||||
return;
|
||||
|
||||
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)
|
||||
{
|
||||
struct serial_rs485 *rs485 = &port->rs485;
|
||||
|
@ -1420,12 +1430,17 @@ static int uart_rs485_config(struct uart_port *port)
|
|||
|
||||
uart_sanitize_serial_rs485(port, rs485);
|
||||
uart_set_rs485_termination(port, rs485);
|
||||
uart_set_rs485_rx_during_tx(port, rs485);
|
||||
|
||||
spin_lock_irqsave(&port->lock, flags);
|
||||
ret = port->rs485_config(port, NULL, rs485);
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
if (ret)
|
||||
if (ret) {
|
||||
memset(rs485, 0, sizeof(*rs485));
|
||||
/* unset GPIOs */
|
||||
gpiod_set_value_cansleep(port->rs485_term_gpio, 0);
|
||||
gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
@ -1464,6 +1479,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
|
|||
return ret;
|
||||
uart_sanitize_serial_rs485(port, &rs485);
|
||||
uart_set_rs485_termination(port, &rs485);
|
||||
uart_set_rs485_rx_during_tx(port, &rs485);
|
||||
|
||||
spin_lock_irqsave(&port->lock, flags);
|
||||
ret = port->rs485_config(port, &tty->termios, &rs485);
|
||||
|
@ -1475,8 +1491,14 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
|
|||
port->ops->set_mctrl(port, port->mctrl);
|
||||
}
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
if (ret)
|
||||
if (ret) {
|
||||
/* restore old GPIO settings */
|
||||
gpiod_set_value_cansleep(port->rs485_term_gpio,
|
||||
!!(port->rs485.flags & SER_RS485_TERMINATE_BUS));
|
||||
gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
|
||||
!!(port->rs485.flags & SER_RS485_RX_DURING_TX));
|
||||
return ret;
|
||||
}
|
||||
|
||||
if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
|
||||
return -EFAULT;
|
||||
|
|
|
@ -226,12 +226,6 @@ 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
|
||||
rs485conf->flags |= SER_RS485_RX_DURING_TX;
|
||||
|
||||
if (rs485conf->flags & SER_RS485_ENABLED) {
|
||||
cr1 = readl_relaxed(port->membase + ofs->cr1);
|
||||
cr3 = readl_relaxed(port->membase + ofs->cr3);
|
||||
|
@ -256,6 +250,8 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
|
|||
|
||||
writel_relaxed(cr3, port->membase + ofs->cr3);
|
||||
writel_relaxed(cr1, port->membase + ofs->cr1);
|
||||
|
||||
rs485conf->flags |= SER_RS485_RX_DURING_TX;
|
||||
} else {
|
||||
stm32_usart_clr_bits(port, ofs->cr3,
|
||||
USART_CR3_DEM | USART_CR3_DEP);
|
||||
|
|
Loading…
Reference in a new issue