serial: 8250_uniphier: Disable clock on probe error path

[PATCH] serial: 8250_uniphier: Disable clock on probe error path

Posted by Malathi A 1 week, 1 day ago

uniphier_uart_probe() calls clk_prepare_enable() on priv->clk before it
reads the port properties, but returns directly when
uart_read_port_properties() fails, leaving the clock prepared and
enabled.

The intent is clear from the surrounding code: the next error path, when
serial8250_register_8250_port() fails, calls clk_disable_unprepare(), as
does uniphier_uart_remove(). Add the missing call so the early failure
behaves the same way.

Found by smatch:

  drivers/tty/serial/8250/8250_uniphier.c:232 uniphier_uart_probe() warn: 'priv->clk' from clk_prepare_enable() not released on lines: 205.

Fixes: 26e8349c0d76 ("serial: 8250_uniphier: Switch to use uart_read_port_properties()")
Signed-off-by: Malathi A <malathi.a2000@gmail.com>
---
 drivers/tty/serial/8250/8250_uniphier.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_uniphier.c b/drivers/tty/serial/8250/8250_uniphier.c
index e3db60bf50c9..52667c1891bb 100644
--- a/drivers/tty/serial/8250/8250_uniphier.c
+++ b/drivers/tty/serial/8250/8250_uniphier.c
@@ -201,8 +201,10 @@ static int uniphier_uart_probe(struct platform_device *pdev)
 	up.port.membase = membase;
 
 	ret = uart_read_port_properties(&up.port);
-	if (ret)
+	if (ret) {
+		clk_disable_unprepare(priv->clk);
 		return ret;
+	}
 
 	up.port.type = PORT_16550A;
 	up.port.iotype = UPIO_MEM32;
-- 
2.43.0

Re: [PATCH] serial: 8250_uniphier: Disable clock on probe error path

Posted by Andy Shevchenko 1 week, 1 day ago

On Wed, Sep 16, 2026 at 09:54:36AM +0000, Malathi A wrote:
> uniphier_uart_probe() calls clk_prepare_enable() on priv->clk before it
> reads the port properties, but returns directly when
> uart_read_port_properties() fails, leaving the clock prepared and
> enabled.
> 
> The intent is clear from the surrounding code: the next error path, when
> serial8250_register_8250_port() fails, calls clk_disable_unprepare(), as
> does uniphier_uart_remove(). Add the missing call so the early failure
> behaves the same way.
> 
> Found by smatch:
> 
>   drivers/tty/serial/8250/8250_uniphier.c:232 uniphier_uart_probe() warn: 'priv->clk' from clk_prepare_enable() not released on lines: 205.

Why not using devm_clk_get_enabled() instead?

-- 
With Best Regards,
Andy Shevchenko