[PATCH 5/6] tty: serial: propagate uart_configure_port failure to uart_add_one_port

[Praveen Talari <praveen.talari@oss.qualcomm.com>]

uart_configure_port() was declared void, so the uart_change_pm(ON)
failure introduced in the previous patch used a bare return that silently
dropped the error and allowed port registration to proceed regardless.

Update serial_core_add_one_port() to check the return value and return
immediately on failure. This propagates up through uart_add_one_port()
to the driver's probe function, allowing the driver to handle or report
the failure rather than silently registering a port that could not be
initialised.

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
 drivers/tty/serial/serial_core.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index e624a67a9395..6cb9e870ba86 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2526,7 +2526,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
 			port->uartclk / 8, port->uartclk / 4);
 }
 
-static void
+static int
 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		    struct uart_port *port)
 {
@@ -2536,7 +2536,7 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 	 * If there isn't a port here, don't do anything further.
 	 */
 	if (!port->iobase && !port->mapbase && !port->membase)
-		return;
+		return 0;
 
 	/*
 	 * Now do the auto configuration stuff.  Note that config_port
@@ -2559,6 +2559,8 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 	}
 
 	if (port->type != PORT_UNKNOWN) {
+		int ret;
+
 		uart_report_port(drv, port);
 
 		/* Synchronize with possible boot console. */
@@ -2566,11 +2568,12 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 			console_lock();
 
 		/* Power up port for set_mctrl() */
-		if (uart_change_pm(state, UART_PM_STATE_ON)) {
+		ret = uart_change_pm(state, UART_PM_STATE_ON);
+		if (ret) {
 			dev_err(port->dev, "failed to power up port\n");
 			if (uart_console(port))
 				console_unlock();
-			return;
+			return ret;
 		}
 
 		/*
@@ -2613,6 +2616,8 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 				dev_err(port->dev, "failed to power down port\n");
 		}
 	}
+
+	return 0;
 }
 
 #ifdef CONFIG_CONSOLE_POLL
@@ -3094,6 +3099,7 @@ static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *u
 	struct tty_port *port;
 	struct device *tty_dev;
 	int num_groups;
+	int ret;
 
 	if (uport->line >= drv->nr)
 		return -EINVAL;
@@ -3135,7 +3141,10 @@ static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *u
 	 * immediately after.
 	 */
 	tty_port_link_device(port, drv->tty_driver, uport->line);
-	uart_configure_port(drv, state, uport);
+
+	ret = uart_configure_port(drv, state, uport);
+	if (ret)
+		return ret;
 
 	port->console = uart_console(uport);
 

-- 
2.34.1