[PATCH -next] serial: milbeaut_usio: Fix error handling in probe and remove

[PATCH -next] serial: milbeaut_usio: Fix error handling in probe and remove

[Wei Yongjun]

devm_clk_get() is used so there is no reason to explicitly call
clk_put() in probe or remove functions. Also remove duplicate assign
for port->membase.

Fixes: ba44dc043004 ("serial: Add Milbeaut serial control")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
---
 drivers/tty/serial/milbeaut_usio.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/tty/serial/milbeaut_usio.c b/drivers/tty/serial/milbeaut_usio.c
index d303b7d4bb20..b960d531300c 100644
--- a/drivers/tty/serial/milbeaut_usio.c
+++ b/drivers/tty/serial/milbeaut_usio.c
@@ -525,8 +525,6 @@ static int mlb_usio_probe(struct platform_device *pdev)
 		ret = -ENODEV;
 		goto failed;
 	}
-	port->mapbase = res->start;
-	port->membase = ioremap(res->start, (res->end - res->start + 1));
 	port->membase = devm_ioremap(&pdev->dev, res->start,
 				resource_size(res));
 
@@ -548,16 +546,12 @@ static int mlb_usio_probe(struct platform_device *pdev)
 	ret = uart_add_one_port(&mlb_usio_uart_driver, port);
 	if (ret) {
 		dev_err(&pdev->dev, "Adding port failed: %d\n", ret);
-		goto failed1;
+		goto failed;
 	}
 	return 0;
 
-failed1:
-	iounmap(port->membase);
-
 failed:
 	clk_disable_unprepare(clk);
-	clk_put(clk);
 
 	return ret;
 }
@@ -569,7 +563,6 @@ static int mlb_usio_remove(struct platform_device *pdev)
 
 	uart_remove_one_port(&mlb_usio_uart_driver, port);
 	clk_disable_unprepare(clk);
-	clk_put(clk);
 
 	return 0;
 }

Re: [PATCH -next] serial: milbeaut_usio: Fix error handling in probe and remove

[Sugaya, Taichi]

Hi,

Thank you for the fixes patch.

On 2019/04/26 0:10, Wei Yongjun wrote:
> devm_clk_get() is used so there is no reason to explicitly call
> clk_put() in probe or remove functions. Also remove duplicate assign
> for port->membase.
> 
> Fixes: ba44dc043004 ("serial: Add Milbeaut serial control")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> ---
>   drivers/tty/serial/milbeaut_usio.c | 9 +--------
>   1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/drivers/tty/serial/milbeaut_usio.c b/drivers/tty/serial/milbeaut_usio.c
> index d303b7d4bb20..b960d531300c 100644
> --- a/drivers/tty/serial/milbeaut_usio.c
> +++ b/drivers/tty/serial/milbeaut_usio.c
> @@ -525,8 +525,6 @@ static int mlb_usio_probe(struct platform_device *pdev)
>   		ret = -ENODEV;
>   		goto failed;
>   	}
> -	port->mapbase = res->start;
> -	port->membase = ioremap(res->start, (res->end - res->start + 1));
>   	port->membase = devm_ioremap(&pdev->dev, res->start,
>   				resource_size(res));
>   
> @@ -548,16 +546,12 @@ static int mlb_usio_probe(struct platform_device *pdev)
>   	ret = uart_add_one_port(&mlb_usio_uart_driver, port);
>   	if (ret) {
>   		dev_err(&pdev->dev, "Adding port failed: %d\n", ret);
> -		goto failed1;
> +		goto failed;
>   	}
>   	return 0;
>   
> -failed1:
> -	iounmap(port->membase);
> -
>   failed:
>   	clk_disable_unprepare(clk);
> -	clk_put(clk);
>   
>   	return ret;
>   }
> @@ -569,7 +563,6 @@ static int mlb_usio_remove(struct platform_device *pdev)
>   
>   	uart_remove_one_port(&mlb_usio_uart_driver, port);
>   	clk_disable_unprepare(clk);
> -	clk_put(clk);
>   
>   	return 0;
>   }
> 
> 
> 

Tested-by: Sugaya Taichi <sugaya.taichi@socionext.com>

Re: [PATCH -next] serial: milbeaut_usio: Fix error handling in probe and remove

[Dan Carpenter]

On Thu, Apr 25, 2019 at 03:10:44PM +0000, Wei Yongjun wrote:
> devm_clk_get() is used so there is no reason to explicitly call
> clk_put() in probe or remove functions.

Your patch is correct, but next time the patch description should be
more clear that this is a double free.  To me the patch description
sounded like it was just tidying up or something instead of fixing a
crash.  It might feel rude to say that the original code will crash, but
we are all human so introducing crashing bugs is not something to be
embarrassed about.

regards,
dan carpenter