backlight: fix device-tree node lookups

PATCH Applied Johan Hovold 3 participants 16 messages Nov 20, 2017 – May 11, 2018

Subsystems (4)

Stable branch Framebuffer layer Multifunction devices (MFD) Backlight class/subsystem

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Johan Hovold

author

2017-11-20 10:45 UTC #0 lore raw

v2 cover backlight: fix device-tree node lookups

A number of drivers have been using the wrong OF helper when doing child-node lookups during probe. This meant that they were doing tree-wide searches rather than matching on child nodes and that the parent node could end up being prematurely freed.

Johan

v2
- add patch 4/4 which fixes two node leaks in as3711_bl instead of marking the leaks using FIXMEs in patch 1/4

Johan Hovold (4):
backlight: as3711_bl: fix device-tree node lookup
backlight: max8925_bl: fix device-tree node lookup
backlight: tps65217_bl: fix device-tree node lookup
backlight: as3711_bl: fix device-tree node leaks

 drivers/video/backlight/as3711_bl.c   | 45 ++++++++++++++++++++++-------------
 drivers/video/backlight/max8925_bl.c  |  4 +++-
 drivers/video/backlight/tps65217_bl.c |  4 ++--
 include/linux/mfd/as3711.h            |  4 ++--
 4 files changed, 36 insertions(+), 21 deletions(-)

Signature · 1 line

2.15.0

Johan Hovold

author

2017-11-20 10:45 UTC #1 lore raw

PATCH v2 1/4 backlight: as3711_bl: fix device-tree node lookup

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 <[email protected]> # 3.10

Cc Guennadi Liakhovetski <[email protected]>

Signed-off-by Johan Hovold <[email protected]>

---
 drivers/video/backlight/as3711_bl.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

drivers/video/backlight/as3711_bl.c +23 ~~-10~~

index 734a9158946b..e55304d5cf07 100644
@@ -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)

Signature · 1 line

2.15.0

Daniel Thompson

Acked-by on v2 1/4

2017-11-20 11:33 UTC #2 lore raw

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

Quoted 10 lines · Johan Hovold

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 <[email protected]> # 3.10
Cc Guennadi Liakhovetski <[email protected]>
Signed-off-by Johan Hovold <[email protected]>

Acked-by Daniel Thompson <[email protected]>

Quoted 89 lines

---
  drivers/video/backlight/as3711_bl.c | 33 +++++++++++++++++++++++----------
  1 file changed, 23 insertions(+), 10 deletions(-)

drivers/video/backlight/as3711_bl.c +23 ~~-10~~

index 734a9158946b..e55304d5cf07 100644
@@ -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)

Lee Jones

Applied

2017-11-29 11:28 UTC #3 lore raw

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

In reply to Johan Hovold

Quoted 6 lines · Johan Hovold

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.

Quoted 7 lines

Fixes 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
Cc stable <[email protected]> # 3.10
Cc Guennadi Liakhovetski <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/video/backlight/as3711_bl.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

Applied, thanks.

Signature · 4 lines

Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â”‚ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Johan Hovold

author

2017-11-20 10:45 UTC #4 lore raw

PATCH v2 2/4 backlight: max8925_bl: fix device-tree node lookup

In reply to Johan Hovold

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, while the child backlight node was leaked.

Fixes 47ec340cb8e2 ("mfd: max8925: Support dt for backlight")

Cc stable <[email protected]> # 3.9

Cc Qing Xu <[email protected]>

Cc Haojian Zhuang <[email protected]>

Signed-off-by Johan Hovold <[email protected]>

---
 drivers/video/backlight/max8925_bl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

drivers/video/backlight/max8925_bl.c +3 -1

index 7b738d60ecc2..f3aa6088f1d9 100644
@@ -116,7 +116,7 @@ static void max8925_backlight_dt_init(struct platform_device *pdev)
 	if (!pdata)
 		return;
 
-	np = of_find_node_by_name(nproot, "backlight");
+	np = of_get_child_by_name(nproot, "backlight");
 	if (!np) {
 		dev_err(&pdev->dev, "failed to find backlight node\n");
 		return;

@@ -125,6 +125,8 @@ static void max8925_backlight_dt_init(struct platform_device *pdev)
 	if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val))
 		pdata->dual_string = val;
 
+	of_node_put(np);
+
 	pdev->dev.platform_data = pdata;
 }

Signature · 1 line

2.15.0

Daniel Thompson

Acked-by on v2 2/4

2017-11-20 11:33 UTC #5 lore raw

Re: [PATCH v2 2/4] backlight: max8925_bl: fix device-tree node lookup

Quoted 4 lines · Johan Hovold

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.

Quoted 8 lines

To make things worse, the parent mfd node was also prematurely freed, while the child backlight node was leaked.
Fixes 47ec340cb8e2 ("mfd: max8925: Support dt for backlight")
Cc stable <[email protected]> # 3.9
Cc Qing Xu <[email protected]>
Cc Haojian Zhuang <[email protected]>
Signed-off-by Johan Hovold <[email protected]>

Didn't I already ack this one?

Acked-by Daniel Thompson <[email protected]>

Quoted 27 lines

---
  drivers/video/backlight/max8925_bl.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)

drivers/video/backlight/max8925_bl.c +3 -1

index 7b738d60ecc2..f3aa6088f1d9 100644
@@ -116,7 +116,7 @@ static void max8925_backlight_dt_init(struct platform_device *pdev)
  	if (!pdata)
  		return;
 
-	np = of_find_node_by_name(nproot, "backlight");
+	np = of_get_child_by_name(nproot, "backlight");
  	if (!np) {
  		dev_err(&pdev->dev, "failed to find backlight node\n");
  		return;

@@ -125,6 +125,8 @@ static void max8925_backlight_dt_init(struct platform_device *pdev)
  	if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val))
  		pdata->dual_string = val;
 
+	of_node_put(np);
+
  	pdev->dev.platform_data = pdata;
  }

Lee Jones

Applied

2017-11-29 11:29 UTC #6 lore raw

Re: [PATCH v2 2/4] backlight: max8925_bl: fix device-tree node lookup

In reply to Johan Hovold

Quoted 7 lines · Johan Hovold

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, while the child backlight node was leaked.

Quoted 8 lines

Fixes 47ec340cb8e2 ("mfd: max8925: Support dt for backlight")
Cc stable <[email protected]> # 3.9
Cc Qing Xu <[email protected]>
Cc Haojian Zhuang <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/video/backlight/max8925_bl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Applied, thanks.

Signature · 4 lines

Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Johan Hovold

author

2017-11-20 10:45 UTC #7 lore raw

PATCH v2 3/4 backlight: tps65217_bl: fix device-tree node lookup

In reply to Johan Hovold

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.

This would only cause trouble if the child node is missing while there is an unrelated node named "backlight" elsewhere in the tree.

Fixes eebfdc17cc6c ("backlight: Add TPS65217 WLED driver")

Cc stable <[email protected]> # 3.7

Cc Matthias Kaehlcke <[email protected]>

Signed-off-by Johan Hovold <[email protected]>

---
 drivers/video/backlight/tps65217_bl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/video/backlight/tps65217_bl.c +2 -2

index 380917c86276..762e3feed097 100644
@@ -184,11 +184,11 @@ static struct tps65217_bl_pdata *
 tps65217_bl_parse_dt(struct platform_device *pdev)
 {
 	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
-	struct device_node *node = of_node_get(tps->dev->of_node);
+	struct device_node *node;
 	struct tps65217_bl_pdata *pdata, *err;
 	u32 val;
 
-	node = of_find_node_by_name(node, "backlight");
+	node = of_get_child_by_name(tps->dev->of_node, "backlight");
 	if (!node)
 		return ERR_PTR(-ENODEV);

Signature · 1 line

2.15.0

Daniel Thompson

Acked-by on v2 3/4

2017-11-20 11:34 UTC #8 lore raw

Re: [PATCH v2 3/4] backlight: tps65217_bl: fix device-tree node lookup

Quoted 11 lines · Johan Hovold

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.
This would only cause trouble if the child node is missing while there is an unrelated node named "backlight" elsewhere in the tree.
Fixes eebfdc17cc6c ("backlight: Add TPS65217 WLED driver")
Cc stable <[email protected]> # 3.7
Cc Matthias Kaehlcke <[email protected]>
Signed-off-by Johan Hovold <[email protected]>

Didn't I already ack this one?

Acked-by Daniel Thompson <[email protected]>

Quoted 23 lines

---
  drivers/video/backlight/tps65217_bl.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

drivers/video/backlight/tps65217_bl.c +2 -2

index 380917c86276..762e3feed097 100644
@@ -184,11 +184,11 @@ static struct tps65217_bl_pdata *
  tps65217_bl_parse_dt(struct platform_device *pdev)
  {
  	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
-	struct device_node *node = of_node_get(tps->dev->of_node);
+	struct device_node *node;
  	struct tps65217_bl_pdata *pdata, *err;
  	u32 val;
 
-	node = of_find_node_by_name(node, "backlight");
+	node = of_get_child_by_name(tps->dev->of_node, "backlight");
  	if (!node)
  		return ERR_PTR(-ENODEV);

Johan Hovold

author

2017-11-20 11:44 UTC #9 lore raw

Re: [PATCH v2 3/4] backlight: tps65217_bl: fix device-tree node lookup

Quoted 10 lines · Daniel Thompson

Quoted 7 lines · Johan Hovold
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.
This would only cause trouble if the child node is missing while there is an unrelated node named "backlight" elsewhere in the tree.

Quoted 6 lines

Quoted 4 lines
Fixes eebfdc17cc6c ("backlight: Add TPS65217 WLED driver")
Cc stable <[email protected]> # 3.7
Cc Matthias Kaehlcke <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Didn't I already ack this one?

Indeed you did (same with the previous one). Sorry about forgetting to add them to v2.

Quoted 1 line

Acked-by Daniel Thompson <[email protected]>

Thanks for the acks.

Johan

Lee Jones

Applied

2017-11-29 11:29 UTC #10 lore raw

Re: [PATCH v2 3/4] backlight: tps65217_bl: fix device-tree node lookup

In reply to Johan Hovold

Quoted 7 lines · Johan Hovold

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.
This would only cause trouble if the child node is missing while there is an unrelated node named "backlight" elsewhere in the tree.

Quoted 7 lines

Fixes eebfdc17cc6c ("backlight: Add TPS65217 WLED driver")
Cc stable <[email protected]> # 3.7
Cc Matthias Kaehlcke <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/video/backlight/tps65217_bl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Applied, thanks.

Signature · 4 lines

Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Johan Hovold

author

2017-11-20 10:45 UTC #11 lore raw

PATCH v2 4/4 backlight: as3711_bl: fix device-tree node leaks

In reply to Johan Hovold

Two framebuffer device-node names were looked up during probe, but were only used as flags to indicate the presence of two framebuffer device.

Drop the unused framebuffer name along with a likewise unused device pointer from the driver data, and update the platform data to pass in booleans instead of the framebuffer strings. This allows us do drop the node references acquired during probe, which would otherwise leak.

Note that there are no other in-kernel users of the modified platform-data fields.

Fixes 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")

Cc Guennadi Liakhovetski <[email protected]>

Signed-off-by Johan Hovold <[email protected]>

---
 drivers/video/backlight/as3711_bl.c | 12 ++++++------
 include/linux/mfd/as3711.h          |  4 ++--
 2 files changed, 8 insertions(+), 8 deletions(-)

drivers/video/backlight/as3711_bl.c +6 -6

index e55304d5cf07..ca544aa764b8 100644
@@ -28,8 +28,6 @@ enum as3711_bl_type {
 
 struct as3711_bl_data {
 	bool powered;
-	const char *fb_name;
-	struct device *fb_dev;
 	enum as3711_bl_type type;
 	int brightness;
 	struct backlight_device *bl;

@@ -273,7 +271,9 @@ static int as3711_backlight_parse_dt(struct device *dev)
 
 	fb = of_parse_phandle(bl, "su1-dev", 0);
 	if (fb) {
-		pdata->su1_fb = fb->full_name;
+		of_node_put(fb);
+
+		pdata->su1_fb = true;
 
 		ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA);
 		if (pdata->su1_max_uA <= 0)

@@ -286,7 +286,9 @@ static int as3711_backlight_parse_dt(struct device *dev)
 	if (fb) {
 		int count = 0;
 
-		pdata->su2_fb = fb->full_name;
+		of_node_put(fb);
+
+		pdata->su2_fb = true;
 
 		ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
 		if (pdata->su2_max_uA <= 0)

@@ -425,7 +427,6 @@ static int as3711_backlight_probe(struct platform_device *pdev)
 
 	if (pdata->su1_fb) {
 		su = &supply->su1;
-		su->fb_name = pdata->su1_fb;
 		su->type = AS3711_BL_SU1;
 
 		max_brightness = min(pdata->su1_max_uA, 31);

@@ -436,7 +437,6 @@ static int as3711_backlight_probe(struct platform_device *pdev)
 
 	if (pdata->su2_fb) {
 		su = &supply->su2;
-		su->fb_name = pdata->su2_fb;
 		su->type = AS3711_BL_SU2;
 
 		switch (pdata->su2_fbprot) {

include/linux/mfd/as3711.h +2 -2

index 34cc85864be5..ddd0b953323b 100644
@@ -108,9 +108,9 @@ struct as3711_regulator_pdata {
 };
 
 struct as3711_bl_pdata {
-	const char *su1_fb;
+	bool su1_fb;
 	int su1_max_uA;
-	const char *su2_fb;
+	bool su2_fb;
 	int su2_max_uA;
 	enum as3711_su2_feedback su2_feedback;
 	enum as3711_su2_fbprot su2_fbprot;

Signature · 1 line

2.15.0

Daniel Thompson

Acked-by on v2 4/4

2017-11-20 11:41 UTC #12 lore raw

Re: [PATCH v2 4/4] backlight: as3711_bl: fix device-tree node leaks

Quoted 8 lines · Johan Hovold

Two framebuffer device-node names were looked up during probe, but were only used as flags to indicate the presence of two framebuffer device.
Drop the unused framebuffer name along with a likewise unused device pointer from the driver data, and update the platform data to pass in booleans instead of the framebuffer strings. This allows us do drop the node references acquired during probe, which would otherwise leak.

Quoted 6 lines

Note that there are no other in-kernel users of the modified platform-data fields.
Fixes 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
Cc Guennadi Liakhovetski <[email protected]>
Signed-off-by Johan Hovold <[email protected]>

Acked-by Daniel Thompson <[email protected]>

Quoted 73 lines

---
  drivers/video/backlight/as3711_bl.c | 12 ++++++------
  include/linux/mfd/as3711.h          |  4 ++--
  2 files changed, 8 insertions(+), 8 deletions(-)

drivers/video/backlight/as3711_bl.c +6 -6

index e55304d5cf07..ca544aa764b8 100644
@@ -28,8 +28,6 @@ enum as3711_bl_type {
 
  struct as3711_bl_data {
  	bool powered;
-	const char *fb_name;
-	struct device *fb_dev;
  	enum as3711_bl_type type;
  	int brightness;
  	struct backlight_device *bl;

@@ -273,7 +271,9 @@ static int as3711_backlight_parse_dt(struct device *dev)
 
  	fb = of_parse_phandle(bl, "su1-dev", 0);
  	if (fb) {
-		pdata->su1_fb = fb->full_name;
+		of_node_put(fb);
+
+		pdata->su1_fb = true;
 
  		ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA);
  		if (pdata->su1_max_uA <= 0)

@@ -286,7 +286,9 @@ static int as3711_backlight_parse_dt(struct device *dev)
  	if (fb) {
  		int count = 0;
 
-		pdata->su2_fb = fb->full_name;
+		of_node_put(fb);
+
+		pdata->su2_fb = true;
 
  		ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
  		if (pdata->su2_max_uA <= 0)

@@ -425,7 +427,6 @@ static int as3711_backlight_probe(struct platform_device *pdev)
 
  	if (pdata->su1_fb) {
  		su = &supply->su1;
-		su->fb_name = pdata->su1_fb;
  		su->type = AS3711_BL_SU1;
 
  		max_brightness = min(pdata->su1_max_uA, 31);

@@ -436,7 +437,6 @@ static int as3711_backlight_probe(struct platform_device *pdev)
 
  	if (pdata->su2_fb) {
  		su = &supply->su2;
-		su->fb_name = pdata->su2_fb;
  		su->type = AS3711_BL_SU2;
 
  		switch (pdata->su2_fbprot) {

include/linux/mfd/as3711.h +2 -2

index 34cc85864be5..ddd0b953323b 100644
@@ -108,9 +108,9 @@ struct as3711_regulator_pdata {
  };
 
  struct as3711_bl_pdata {
-	const char *su1_fb;
+	bool su1_fb;
  	int su1_max_uA;
-	const char *su2_fb;
+	bool su2_fb;
  	int su2_max_uA;
  	enum as3711_su2_feedback su2_feedback;
  	enum as3711_su2_fbprot su2_fbprot;

Lee Jones

Applied

2017-11-29 11:29 UTC #13 lore raw

Re: [PATCH v2 4/4] backlight: as3711_bl: fix device-tree node leaks

In reply to Johan Hovold

Quoted 11 lines · Johan Hovold

Two framebuffer device-node names were looked up during probe, but were only used as flags to indicate the presence of two framebuffer device.
Drop the unused framebuffer name along with a likewise unused device pointer from the driver data, and update the platform data to pass in booleans instead of the framebuffer strings. This allows us do drop the node references acquired during probe, which would otherwise leak.
Note that there are no other in-kernel users of the modified platform-data fields.

Quoted 7 lines

Fixes 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
Cc Guennadi Liakhovetski <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/video/backlight/as3711_bl.c | 12 ++++++------
 include/linux/mfd/as3711.h          |  4 ++--
 2 files changed, 8 insertions(+), 8 deletions(-)

Applied, thanks.

Signature · 4 lines

Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â”‚ Open source software for ARM SoCs
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Johan Hovold

author

2018-05-11 07:27 UTC #14 lore raw

In reply to Johan Hovold

Hi Lee,

Quoted 10 lines · Johan Hovold

A number of drivers have been using the wrong OF helper when doing child-node lookups during probe. This meant that they were doing tree-wide searches rather than matching on child nodes and that the parent node could end up being prematurely freed.
Johan Hovold (4):
backlight: as3711_bl: fix device-tree node lookup
backlight: max8925_bl: fix device-tree node lookup
backlight: tps65217_bl: fix device-tree node lookup
backlight: as3711_bl: fix device-tree node leaks

It appears these four have been sitting in your for-backlight-fixes branch for half a year now without being forwarded to Linus.

Don't get many backlight fixes these days, huh? ;)

Thanks,
Johan

Lee Jones

2018-05-11 08:13 UTC #15 lore raw

Quoted 14 lines · Johan Hovold

Hi Lee,
Quoted 10 lines · Johan Hovold
A number of drivers have been using the wrong OF helper when doing child-node lookups during probe. This meant that they were doing tree-wide searches rather than matching on child nodes and that the parent node could end up being prematurely freed.
Johan Hovold (4):
backlight: as3711_bl: fix device-tree node lookup
backlight: max8925_bl: fix device-tree node lookup
backlight: tps65217_bl: fix device-tree node lookup
backlight: as3711_bl: fix device-tree node leaks

Quoted 4 lines

It appears these four have been sitting in your for-backlight-fixes branch for half a year now without being forwarded to Linus.
Don't get many backlight fixes these days, huh? ;)

Ha! To be honest I think those patches are the only 4 -fixes I've *ever* had for Backlight. :)

I have pulled them into the main branch, so they won't be forgotten again. Sorry for the delay.

Signature · 4 lines

Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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