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Subject[PATCH 2/4] drm/imx: imx-ldb: add missing of_node_puts
Date
The device node iterators perform an of_node_get on each
iteration, so a jump out of the loop requires an of_node_put.

Move the initialization channel->child = child; down to just
before the call to imx_ldb_register so that intervening failures
don't need to clear it. Add a label at the end of the function to
do all the of_node_puts.

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

// <smpl>
@@
expression root,e;
local idexpression child;
iterator name for_each_child_of_node;
@@

for_each_child_of_node(root, child) {
... when != of_node_put(child)
when != e = child
(
return child;
|
* return ...;
)
...
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
This changes the semantics, with respect to the availability of the child
field, and has not been tested.

drivers/gpu/drm/imx/imx-ldb.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c
index 2c5bbe3..e31e263 100644
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@@ -643,8 +643,10 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
int bus_format;

ret = of_property_read_u32(child, "reg", &i);
- if (ret || i < 0 || i > 1)
- return -EINVAL;
+ if (ret || i < 0 || i > 1) {
+ ret = -EINVAL;
+ goto free_child;
+ }

if (!of_device_is_available(child))
continue;
@@ -657,7 +659,6 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
channel = &imx_ldb->channel[i];
channel->ldb = imx_ldb;
channel->chno = i;
- channel->child = child;

/*
* The output port is port@4 with an external 4-port mux or
@@ -667,13 +668,13 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
imx_ldb->lvds_mux ? 4 : 2, 0,
&channel->panel, &channel->bridge);
if (ret && ret != -ENODEV)
- return ret;
+ goto free_child;

/* panel ddc only if there is no bridge */
if (!channel->bridge) {
ret = imx_ldb_panel_ddc(dev, channel, child);
if (ret)
- return ret;
+ goto free_child;
}

bus_format = of_get_bus_format(dev, child);
@@ -689,18 +690,26 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
if (bus_format < 0) {
dev_err(dev, "could not determine data mapping: %d\n",
bus_format);
- return bus_format;
+ ret = bus_format;
+ goto free_child;
}
channel->bus_format = bus_format;
+ channel->child = child;

ret = imx_ldb_register(drm, channel);
- if (ret)
- return ret;
+ if (ret) {
+ channel->child = NULL;
+ goto free_child;
+ }
}

dev_set_drvdata(dev, imx_ldb);

return 0;
+
+free_child:
+ of_node_put(child);
+ return ret;
}

static void imx_ldb_unbind(struct device *dev, struct device *master,
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