diff mbox

[v2,1/4] backlight: as3711_bl: fix device-tree node lookup

Message ID 20171120104547.2639-2-johan@kernel.org (mailing list archive)
State New, archived
Headers show

Commit Message

Johan Hovold Nov. 20, 2017, 10:45 a.m. UTC
Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

To make things worse, the parent mfd node was also prematurely freed.

Fixes: 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
Cc: stable <stable@vger.kernel.org>     # 3.10
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/video/backlight/as3711_bl.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

Comments

Daniel Thompson Nov. 20, 2017, 11:33 a.m. UTC | #1
On 20/11/17 10:45, Johan Hovold wrote:
> Fix child-node lookup during probe, which ended up searching the whole
> device tree depth-first starting at the parent rather than just matching
> on its children.
> 
> To make things worse, the parent mfd node was also prematurely freed.
> 
> Fixes: 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
> Cc: stable <stable@vger.kernel.org>     # 3.10
> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> Signed-off-by: Johan Hovold <johan@kernel.org>

Acked-by: Daniel Thompson <daniel.thompson@linaro.org>


> ---
>   drivers/video/backlight/as3711_bl.c | 33 +++++++++++++++++++++++----------
>   1 file changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/video/backlight/as3711_bl.c b/drivers/video/backlight/as3711_bl.c
> index 734a9158946b..e55304d5cf07 100644
> --- a/drivers/video/backlight/as3711_bl.c
> +++ b/drivers/video/backlight/as3711_bl.c
> @@ -262,10 +262,10 @@ static int as3711_bl_register(struct platform_device *pdev,
>   static int as3711_backlight_parse_dt(struct device *dev)
>   {
>   	struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
> -	struct device_node *bl =
> -		of_find_node_by_name(dev->parent->of_node, "backlight"), *fb;
> +	struct device_node *bl, *fb;
>   	int ret;
>   
> +	bl = of_get_child_by_name(dev->parent->of_node, "backlight");
>   	if (!bl) {
>   		dev_dbg(dev, "backlight node not found\n");
>   		return -ENODEV;
> @@ -279,7 +279,7 @@ static int as3711_backlight_parse_dt(struct device *dev)
>   		if (pdata->su1_max_uA <= 0)
>   			ret = -EINVAL;
>   		if (ret < 0)
> -			return ret;
> +			goto err_put_bl;
>   	}
>   
>   	fb = of_parse_phandle(bl, "su2-dev", 0);
> @@ -292,7 +292,7 @@ static int as3711_backlight_parse_dt(struct device *dev)
>   		if (pdata->su2_max_uA <= 0)
>   			ret = -EINVAL;
>   		if (ret < 0)
> -			return ret;
> +			goto err_put_bl;
>   
>   		if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
>   			pdata->su2_feedback = AS3711_SU2_VOLTAGE;
> @@ -314,8 +314,10 @@ static int as3711_backlight_parse_dt(struct device *dev)
>   			pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
>   			count++;
>   		}
> -		if (count != 1)
> -			return -EINVAL;
> +		if (count != 1) {
> +			ret = -EINVAL;
> +			goto err_put_bl;
> +		}
>   
>   		count = 0;
>   		if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
> @@ -334,8 +336,10 @@ static int as3711_backlight_parse_dt(struct device *dev)
>   			pdata->su2_fbprot = AS3711_SU2_GPIO4;
>   			count++;
>   		}
> -		if (count != 1)
> -			return -EINVAL;
> +		if (count != 1) {
> +			ret = -EINVAL;
> +			goto err_put_bl;
> +		}
>   
>   		count = 0;
>   		if (of_find_property(bl, "su2-auto-curr1", NULL)) {
> @@ -355,11 +359,20 @@ static int as3711_backlight_parse_dt(struct device *dev)
>   		 * At least one su2-auto-curr* must be specified iff
>   		 * AS3711_SU2_CURR_AUTO is used
>   		 */
> -		if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO))
> -			return -EINVAL;
> +		if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) {
> +			ret = -EINVAL;
> +			goto err_put_bl;
> +		}
>   	}
>   
> +	of_node_put(bl);
> +
>   	return 0;
> +
> +err_put_bl:
> +	of_node_put(bl);
> +
> +	return ret;
>   }
>   
>   static int as3711_backlight_probe(struct platform_device *pdev)
> 
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Lee Jones Nov. 29, 2017, 11:28 a.m. UTC | #2
On Mon, 20 Nov 2017, Johan Hovold wrote:

> Fix child-node lookup during probe, which ended up searching the whole
> device tree depth-first starting at the parent rather than just matching
> on its children.
> 
> To make things worse, the parent mfd node was also prematurely freed.
> 
> Fixes: 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
> Cc: stable <stable@vger.kernel.org>     # 3.10
> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>  drivers/video/backlight/as3711_bl.c | 33 +++++++++++++++++++++++----------
>  1 file changed, 23 insertions(+), 10 deletions(-)

Applied, thanks.
diff mbox

Patch

diff --git a/drivers/video/backlight/as3711_bl.c b/drivers/video/backlight/as3711_bl.c
index 734a9158946b..e55304d5cf07 100644
--- a/drivers/video/backlight/as3711_bl.c
+++ b/drivers/video/backlight/as3711_bl.c
@@ -262,10 +262,10 @@  static int as3711_bl_register(struct platform_device *pdev,
 static int as3711_backlight_parse_dt(struct device *dev)
 {
 	struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
-	struct device_node *bl =
-		of_find_node_by_name(dev->parent->of_node, "backlight"), *fb;
+	struct device_node *bl, *fb;
 	int ret;
 
+	bl = of_get_child_by_name(dev->parent->of_node, "backlight");
 	if (!bl) {
 		dev_dbg(dev, "backlight node not found\n");
 		return -ENODEV;
@@ -279,7 +279,7 @@  static int as3711_backlight_parse_dt(struct device *dev)
 		if (pdata->su1_max_uA <= 0)
 			ret = -EINVAL;
 		if (ret < 0)
-			return ret;
+			goto err_put_bl;
 	}
 
 	fb = of_parse_phandle(bl, "su2-dev", 0);
@@ -292,7 +292,7 @@  static int as3711_backlight_parse_dt(struct device *dev)
 		if (pdata->su2_max_uA <= 0)
 			ret = -EINVAL;
 		if (ret < 0)
-			return ret;
+			goto err_put_bl;
 
 		if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
 			pdata->su2_feedback = AS3711_SU2_VOLTAGE;
@@ -314,8 +314,10 @@  static int as3711_backlight_parse_dt(struct device *dev)
 			pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
 			count++;
 		}
-		if (count != 1)
-			return -EINVAL;
+		if (count != 1) {
+			ret = -EINVAL;
+			goto err_put_bl;
+		}
 
 		count = 0;
 		if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
@@ -334,8 +336,10 @@  static int as3711_backlight_parse_dt(struct device *dev)
 			pdata->su2_fbprot = AS3711_SU2_GPIO4;
 			count++;
 		}
-		if (count != 1)
-			return -EINVAL;
+		if (count != 1) {
+			ret = -EINVAL;
+			goto err_put_bl;
+		}
 
 		count = 0;
 		if (of_find_property(bl, "su2-auto-curr1", NULL)) {
@@ -355,11 +359,20 @@  static int as3711_backlight_parse_dt(struct device *dev)
 		 * At least one su2-auto-curr* must be specified iff
 		 * AS3711_SU2_CURR_AUTO is used
 		 */
-		if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO))
-			return -EINVAL;
+		if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) {
+			ret = -EINVAL;
+			goto err_put_bl;
+		}
 	}
 
+	of_node_put(bl);
+
 	return 0;
+
+err_put_bl:
+	of_node_put(bl);
+
+	return ret;
 }
 
 static int as3711_backlight_probe(struct platform_device *pdev)