From: John Ogness <john.ogness@linutronix.de>
Date: Mon, 2 Oct 2023 15:30:43 +0000
Subject: [PATCH 133/134] serial: 8250: revert "drop lockdep annotation from
 serial8250_clear_IER()"
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz

The 8250 driver no longer depends on @oops_in_progress and
will no longer violate the port->lock locking constraints.

This reverts commit 3d9e6f556e235ddcdc9f73600fdd46fe1736b090.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/tty/serial/8250/8250_port.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -728,6 +728,9 @@ static void __serial8250_clear_IER(struc
 
 static inline void serial8250_clear_IER(struct uart_8250_port *up)
 {
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
 	__serial8250_clear_IER(up);
 }