[PATCH v3 1/4] serial: revert guards in uart_wait_modem_status()

[Johan Hovold <johan@kernel.org>]

Mixing scope-based and regular cleanup is discouraged and
uart_port_deref() used by uart_wait_modem_status() falls in the latter
category.

Revert the premature guard conversion in preparation for fixing a hangup
race.

Fixes: 56609c050051 ("serial: serial_core: use guard()s")
Cc: stable@vger.kernel.org	# 6.18
Cc: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/tty/serial/serial_core.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 95774b0f1484..1553bc6cbe7b 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1213,15 +1213,16 @@ static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
 	uport = uart_port_ref(state);
 	if (!uport)
 		return -EIO;
-	scoped_guard(uart_port_lock_irq, uport) {
-		memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
-		uart_enable_ms(uport);
-	}
+	uart_port_lock_irq(uport);
+	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
+	uart_enable_ms(uport);
+	uart_port_unlock_irq(uport);
 
 	add_wait_queue(&port->delta_msr_wait, &wait);
 	for (;;) {
-		scoped_guard(uart_port_lock_irq, uport)
-			memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
+		uart_port_lock_irq(uport);
+		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
+		uart_port_unlock_irq(uport);
 
 		set_current_state(TASK_INTERRUPTIBLE);
 
-- 
2.55.0