[PATCH] [media] media: mtk-mdp: fix reference count on old device tree

[PATCH] [media] media: mtk-mdp: fix reference count on old device tree

[Matthias Brugger]

of_get_next_child() increments the reference count of the returning
device_node. Decrement it in the check if we are using the old or the
new DTB.

Fixes: ba1f1f70c2c0 ("[media] media: mtk-mdp: Fix mdp device tree")
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
---
 drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
index bbb24fb95b95..bafe53c5d54a 100644
--- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
+++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
@@ -118,7 +118,9 @@ static int mtk_mdp_probe(struct platform_device *pdev)
 	mutex_init(&mdp->vpulock);
 
 	/* Old dts had the components as child nodes */
-	if (of_get_next_child(dev->of_node, NULL)) {
+	parent = of_get_next_child(dev->of_node, NULL);
+	if (parent) {
+		of_node_put(parent);
 		parent = dev->of_node;
 		dev_warn(dev, "device tree is out of date\n");
 	} else {
-- 
2.21.0

Re: [PATCH] [media] media: mtk-mdp: fix reference count on old device tree

[Greg KH]

On Fri, Jun 21, 2019 at 01:32:50PM +0200, Matthias Brugger wrote:
> of_get_next_child() increments the reference count of the returning
> device_node. Decrement it in the check if we are using the old or the
> new DTB.
> 
> Fixes: ba1f1f70c2c0 ("[media] media: mtk-mdp: Fix mdp device tree")
> Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
> ---
>  drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

Re: [PATCH] [media] media: mtk-mdp: fix reference count on old device tree

[Matthias Brugger]

On 21/06/2019 13:32, Matthias Brugger wrote:
> of_get_next_child() increments the reference count of the returning
> device_node. Decrement it in the check if we are using the old or the
> new DTB.
> 
> Fixes: ba1f1f70c2c0 ("[media] media: mtk-mdp: Fix mdp device tree")
> Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Any comments on that?

> ---
>  drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> index bbb24fb95b95..bafe53c5d54a 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> @@ -118,7 +118,9 @@ static int mtk_mdp_probe(struct platform_device *pdev)
>  	mutex_init(&mdp->vpulock);
>  
>  	/* Old dts had the components as child nodes */
> -	if (of_get_next_child(dev->of_node, NULL)) {
> +	parent = of_get_next_child(dev->of_node, NULL);
> +	if (parent) {
> +		of_node_put(parent);
>  		parent = dev->of_node;
>  		dev_warn(dev, "device tree is out of date\n");
>  	} else {
> 

Re: [PATCH] [media] media: mtk-mdp: fix reference count on old device tree

[houlong wei]

On Mon, 2019-07-08 at 17:06 +0800, Matthias Brugger wrote:
> 
> On 21/06/2019 13:32, Matthias Brugger wrote:
> > of_get_next_child() increments the reference count of the returning
> > device_node. Decrement it in the check if we are using the old or the
> > new DTB.
> > 
> > Fixes: ba1f1f70c2c0 ("[media] media: mtk-mdp: Fix mdp device tree")
> > Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
> 
> Any comments on that?
> 

Hi Matthias,
Thanks for fixing the bug. Sorry to reply late~

Acked-by: Houlong Wei <houlong.wei@mediatek.com>


> > ---
> >  drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > index bbb24fb95b95..bafe53c5d54a 100644
> > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
> > @@ -118,7 +118,9 @@ static int mtk_mdp_probe(struct platform_device *pdev)
> >  	mutex_init(&mdp->vpulock);
> >  
> >  	/* Old dts had the components as child nodes */
> > -	if (of_get_next_child(dev->of_node, NULL)) {
> > +	parent = of_get_next_child(dev->of_node, NULL);
> > +	if (parent) {
> > +		of_node_put(parent);
> >  		parent = dev->of_node;
> >  		dev_warn(dev, "device tree is out of date\n");
> >  	} else {
> >