Lino Sanfilippo wrote on 2023-12-29 16:03:
Hi,
On 25.12.23 at 13:31, Maarten Brock wrote:
Lino Sanfilippo wrote on 2023-12-25 12:35:
diff --git a/drivers/tty/serial/serial_core.c
b/drivers/tty/serial/serial_core.c
+static void uart_set_rs485_rx_during_tx(struct uart_port *port,
+ const struct serial_rs485 *rs485)
+{
+ if (!(rs485->flags & SER_RS485_ENABLED))
+ return;
How about checking port->rs485_rx_during_tx_gpio here against NULL
instead of
before every call?
gpiod_set_value_cansleep() already checks for a NULL pointer, so doing
this check in the caller is not needed.
Ah, sorry, you're right.
+ gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio,
+ !!(rs485->flags & SER_RS485_RX_DURING_TX));
+}
+
@@ -1457,6 +1472,7 @@ 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);
uart_port_lock_irqsave(port, &flags);
ret = port->rs485_config(port, &tty->termios, &rs485);
@@ -1468,8 +1484,14 @@ static int uart_set_rs485_config(struct
tty_struct *tty, struct uart_port *port,
port->ops->set_mctrl(port, port->mctrl);
}
uart_port_unlock_irqrestore(port, 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));
This does not look like restoring.
Hmm. The rx-during-tx and terminate-bus GPIOs may have changed before
the
drivers rs485_config() was called. If that function fails, the GPIOs
are set back to the values they had before (i.e what is still stored in
the ports serial_rs485 struct). So what is wrong with the term
"restore"?
Oops, I missed that too that port-rs485 is not updated in this case.
Kind Regards,
Maarten Brock
