[02/12] drm/tegra: rgb: add missing of_node_put after of_device_is_available

Add an of_node_put when a tested device node is not available.

The semantic patch that fixes this problem is as follows
(http://coccinelle.lip6.fr):

// <smpl>
@@
identifier f;
local idexpression e;
expression x;
@@

e = f(...);
... when != of_node_put(e)
    when != x = e
    when != e = x
    when any
if (<+...of_device_is_available(e)...+>) {
  ... when != of_node_put(e)
(
  return e;
|
+ of_node_put(e);
  return ...;
)
}
// </smpl>

Fixes: d8f4a9eda0067 ("drm: Add NVIDIA Tegra20 support")
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/gpu/drm/tegra/rgb.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

On 2/23/2019 6:50 PM, Julia Lawall wrote:
> Add an of_node_put when a tested device node is not available.
>
> The semantic patch that fixes this problem is as follows
> (http://coccinelle.lip6.fr):
>
> // <smpl>
> @@
> identifier f;
> local idexpression e;
> expression x;
> @@
>
> e = f(...);
> ... when != of_node_put(e)
>      when != x = e
>      when != e = x
>      when any
> if (<+...of_device_is_available(e)...+>) {
>    ... when != of_node_put(e)
> (
>    return e;
> |
> + of_node_put(e);
>    return ...;
> )
> }
> // </smpl>
>
> Fixes: d8f4a9eda0067 ("drm: Add NVIDIA Tegra20 support")
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>

Cheers,
-Mukesh
>
> ---
>   drivers/gpu/drm/tegra/rgb.c |    4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff -u -p a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
> --- a/drivers/gpu/drm/tegra/rgb.c
> +++ b/drivers/gpu/drm/tegra/rgb.c
> @@ -221,8 +221,10 @@ int tegra_dc_rgb_probe(struct tegra_dc *
>   	int err;
>   
>   	np = of_get_child_by_name(dc->dev->of_node, "rgb");
> -	if (!np || !of_device_is_available(np))
> +	if (!np || !of_device_is_available(np)) {
> +		of_node_put(np);
>   		return -ENODEV;
> +	}
>   
>   	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
>   	if (!rgb)
>

> @@ -221,8 +221,10 @@  int tegra_dc_rgb_probe(struct tegra_dc *
>  	int err;
>
>  	np = of_get_child_by_name(dc->dev->of_node, "rgb");
> -	if (!np || !of_device_is_available(np))
> +	if (!np || !of_device_is_available(np)) {
> +		of_node_put(np);
>  		return -ENODEV;
> +	}
>
>  	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
>  	if (!rgb)

How do you think about to move this function call to an additional jump target
for the desired exception handling?

Regards,
Markus