[PATCH] serial: meson: unregister the UART driver if port registration fails

[Wentao Liang]

meson_uart_probe() registers the shared uart_driver on the first port and
relies on meson_uart_remove() to unregister it once the last port is
removed.  If uart_add_one_port() fails, probe returns an error, so remove
is never called and the driver stays registered, leaking its tty driver
and per-port state.

Remember whether this probe registered the driver and unregister it again
when adding the port fails.

Fixes: e71aab9d6132 ("tty: serial: meson: apply ttyS devname instead of ttyAML for new SoCs")
Cc: stable at vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab at iscas.ac.cn>
---
 drivers/tty/serial/meson_uart.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index a6cb2a535f9d..a51362f73dee 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -702,6 +702,7 @@ static int meson_uart_probe(struct platform_device *pdev)
 	int ret = 0;
 	int irq;
 	bool has_rtscts;
+	bool registered = false;
 
 	if (pdev->dev.of_node)
 		pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -753,6 +754,7 @@ static int meson_uart_probe(struct platform_device *pdev)
 		if (ret)
 			return dev_err_probe(&pdev->dev, ret,
 					     "can't register uart driver\n");
+		registered = true;
 	}
 
 	port->iotype = UPIO_MEM;
@@ -781,8 +783,11 @@ static int meson_uart_probe(struct platform_device *pdev)
 	}
 
 	ret = uart_add_one_port(uart_driver, port);
-	if (ret)
+	if (ret) {
 		meson_ports[pdev->id] = NULL;
+		if (registered)
+			uart_unregister_driver(uart_driver);
+	}
 
 	return ret;
 }
-- 
2.34.1