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@xxxxxxxxxxxxxxx
Signed-off-by: Vitalii Mordan <mordan@xxxxxxxxx>
---
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");
return PTR_ERR(owl_port->clk);
}
- 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);
return -EINVAL;
}
owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY;
@@ -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
