1 files changed, 20 insertions, 24 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index f797c971cd82..124524ecfe26 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1916,24 +1916,12 @@ static inline bool uart_console_enabled(struct uart_port *port)
 	return uart_console(port) && (port->cons->flags & CON_ENABLED);
 }
 
-static void __uart_port_spin_lock_init(struct uart_port *port)
+static void uart_port_spin_lock_init(struct uart_port *port)
 {
 	spin_lock_init(&port->lock);
 	lockdep_set_class(&port->lock, &port_lock_key);
 }
 
-/*
- * Ensure that the serial console lock is initialised early.
- * If this port is a console, then the spinlock is already initialised.
- */
-static inline void uart_port_spin_lock_init(struct uart_port *port)
-{
-	if (uart_console(port))
-		return;
-
-	__uart_port_spin_lock_init(port);
-}
-
 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
 /**
  *	uart_console_write - write a console message to a serial port
@@ -2086,7 +2074,15 @@ uart_set_options(struct uart_port *port, struct console *co,
 	struct ktermios termios;
 	static struct ktermios dummy;
 
-	uart_port_spin_lock_init(port);
+	/*
+	 * Ensure that the serial-console lock is initialised early.
+	 *
+	 * Note that the console-enabled check is needed because of kgdboc,
+	 * which can end up calling uart_set_options() for an already enabled
+	 * console via tty_find_polling_driver() and uart_poll_init().
+	 */
+	if (!uart_console_enabled(port) && !port->console_reinit)
+		uart_port_spin_lock_init(port);
 
 	memset(&termios, 0, sizeof(struct ktermios));
 
@@ -2379,13 +2375,6 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		uart_change_pm(state, UART_PM_STATE_ON);
 
 		/*
-		 * If this driver supports console, and it hasn't been
-		 * successfully registered yet, initialise spin lock for it.
-		 */
-		if (port->cons && !(port->cons->flags & CON_ENABLED))
-			__uart_port_spin_lock_init(port);
-
-		/*
 		 * Ensure that the modem control lines are de-activated.
 		 * keep the DTR setting that is set in uart_set_options()
 		 * We probably don't need a spinlock around this, but
@@ -2801,10 +2790,12 @@ static ssize_t console_store(struct device *dev,
 		if (oldconsole && !newconsole) {
 			ret = unregister_console(uport->cons);
 		} else if (!oldconsole && newconsole) {
-			if (uart_console(uport))
+			if (uart_console(uport)) {
+				uport->console_reinit = 1;
 				register_console(uport->cons);
-			else
+			} else {
 				ret = -ENOENT;
+			}
 		}
 	} else {
 		ret = -ENXIO;
@@ -2900,7 +2891,12 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 		goto out;
 	}
 
-	uart_port_spin_lock_init(uport);
+	/*
+	 * If this port is in use as a console then the spinlock is already
+	 * initialised.
+	 */
+	if (!uart_console_enabled(uport))
+		uart_port_spin_lock_init(uport);
 
 	if (uport->cons && uport->dev)
 		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);