[PATCH 5.15 08/10] serial: fixup backport of "serial: Deassert Transmit Enable on probe in driver-specific way"

[PATCH 5.15 08/10] serial: fixup backport of "serial: Deassert Transmit Enable on probe in driver-specific way"

[Greg Kroah-Hartman]

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

When 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in
driver-specific way") got backported to 5.15.y, there known as
b079d3775237, some hunks were accidentally left out.

In fsl_lpuart.c, this amounts to uart_remove_one_port() being called
in an error path despite uart_add_one_port() not having been called.

In serial_core.c, it is possible that the omission in
uart_suspend_port() is harmless, but the backport did have the
corresponding hunk in uart_resume_port(), it runs counter to the
original commit's intention of

  Skip any invocation of ->set_mctrl() if RS485 is enabled.

and it's certainly better to be aligned with upstream.

Fixes: b079d3775237 ("serial: Deassert Transmit Enable on probe in driver-specific way")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/fsl_lpuart.c  |    2 +-
 drivers/tty/serial/serial_core.c |    3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2784,9 +2784,9 @@ static int lpuart_probe(struct platform_
 	return 0;
 
 failed_irq_request:
-failed_get_rs485:
 	uart_remove_one_port(&lpuart_reg, &sport->port);
 failed_attach_port:
+failed_get_rs485:
 failed_reset:
 	lpuart_disable_clks(sport);
 	return ret;
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2225,7 +2225,8 @@ int uart_suspend_port(struct uart_driver
 
 		spin_lock_irq(&uport->lock);
 		ops->stop_tx(uport);
-		ops->set_mctrl(uport, 0);
+		if (!(uport->rs485.flags & SER_RS485_ENABLED))
+			ops->set_mctrl(uport, 0);
 		ops->stop_rx(uport);
 		spin_unlock_irq(&uport->lock);