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authorRob Herring <rob.herring@calxeda.com>2011-09-20 13:02:54 -0500
committerRob Herring <rob.herring@calxeda.com>2011-10-05 07:39:37 -0500
commitdc9372808412edbc653a675a526c2ee6c0c14a91 (patch)
tree5c6a2252c1de2720e7783a48f5b144003176cf65 /drivers
parentf910b831c9647d85dc6f13e3b8698d10cbfd5011 (diff)
downloadlinux-stericsson-dc9372808412edbc653a675a526c2ee6c0c14a91.tar.gz
of/irq: of_irq_find_parent: check for parent equal to child
An interrupt controller may often implicitly inherit itself from a parent node when in fact the controller is the interrupt root controller. Guard against the case of child == parent and return NULL in this case. This can also be fixed by adding an explicit "interrupt-parent;" to a root interrupt controller node. Based on code from Grant Likely. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/of/irq.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 9f689f1da0fc..6a5b5e777dd2 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -58,27 +58,27 @@ EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
*/
struct device_node *of_irq_find_parent(struct device_node *child)
{
- struct device_node *p;
+ struct device_node *p, *c = child;
const __be32 *parp;
- if (!of_node_get(child))
+ if (!of_node_get(c))
return NULL;
do {
- parp = of_get_property(child, "interrupt-parent", NULL);
+ parp = of_get_property(c, "interrupt-parent", NULL);
if (parp == NULL)
- p = of_get_parent(child);
+ p = of_get_parent(c);
else {
if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
p = of_node_get(of_irq_dflt_pic);
else
p = of_find_node_by_phandle(be32_to_cpup(parp));
}
- of_node_put(child);
- child = p;
+ of_node_put(c);
+ c = p;
} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
- return p;
+ return (p == child) ? NULL : p;
}
/**