On Thu, Feb 13, 2025 at 02:24:16PM +0300, Vitalii Mordan wrote:
If owl_port->clk was enabled in owl_uart_probe(), it must be disabled in all error paths to ensure proper cleanup. However, if uart_add_one_port() returns an error in owl_uart_probe(), the owl_port->clk clock will not be disabled.
Use the devm_clk_get_enabled() helper function to ensure proper call balance for owl_port->clk.
Found by Linux Verification Center (linuxtesting.org) with Klever.
Fixes: abf42d2f333b ("tty: serial: owl: add "much needed" clk_prepare_enable()") Cc: stable@vger.kernel.org Signed-off-by: Vitalii Mordan mordan@ispras.ru
Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org
- Mani
drivers/tty/serial/owl-uart.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c index 0542882cfbbe..64446820437c 100644 --- a/drivers/tty/serial/owl-uart.c +++ b/drivers/tty/serial/owl-uart.c @@ -680,18 +680,12 @@ static int owl_uart_probe(struct platform_device *pdev) if (!owl_port) return -ENOMEM;
- owl_port->clk = devm_clk_get(&pdev->dev, NULL);
- owl_port->clk = devm_clk_get_enabled(&pdev->dev, NULL); if (IS_ERR(owl_port->clk)) {
dev_err(&pdev->dev, "could not get clk\n");
dev_err(&pdev->dev, "could not get and enable clk\n");
- ret = clk_prepare_enable(owl_port->clk);
- if (ret) {
dev_err(&pdev->dev, "could not enable clk\n");return ret;- }
- owl_port->port.dev = &pdev->dev; owl_port->port.line = pdev->id; owl_port->port.type = PORT_OWL;
@@ -701,7 +695,6 @@ static int owl_uart_probe(struct platform_device *pdev) owl_port->port.uartclk = clk_get_rate(owl_port->clk); if (owl_port->port.uartclk == 0) { dev_err(&pdev->dev, "clock rate is zero\n");
clk_disable_unprepare(owl_port->clk);@@ -725,7 +718,6 @@ static void owl_uart_remove(struct platform_device *pdev) uart_remove_one_port(&owl_uart_driver, &owl_port->port); owl_uart_ports[pdev->id] = NULL;
- clk_disable_unprepare(owl_port->clk);
} static struct platform_driver owl_uart_platform_driver = { -- 2.25.1