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@xxxxxxx> --- 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,
