[PATCH 3.16 130/366] backlight: as3711_bl: Fix Device Tree node lookup

Ben Hutchings
2018-11-11T20:07:02Z

From: Johan Hovold <johan@kernel.org>

commit 4a9c8bb2aca5b5a2a15744333729745dd9903562 upstream.

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")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/video/backlight/as3711_bl.c | 33 ++++++++++++++++++++---------
1 file changed, 23 insertions(+), 10 deletions(-)

--- a/drivers/video/backlight/as3711_bl.c
+++ b/drivers/video/backlight/as3711_bl.c
@@ -262,10 +262,10 @@ static int as3711_bl_register(struct pla
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(str
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(str
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(str
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(str
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(str
* 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)