diff options
| author | Rob Herring <rob.herring@calxeda.com> | 2011-09-20 22:02:54 +0400 |
|---|---|---|
| committer | Rob Herring <rob.herring@calxeda.com> | 2011-10-05 16:39:37 +0400 |
| commit | dc9372808412edbc653a675a526c2ee6c0c14a91 (patch) | |
| tree | 5c6a2252c1de2720e7783a48f5b144003176cf65 | |
| parent | f910b831c9647d85dc6f13e3b8698d10cbfd5011 (diff) | |
| download | linux-dc9372808412edbc653a675a526c2ee6c0c14a91.tar.xz | |
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>
| -rw-r--r-- | drivers/of/irq.c | 14 |
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; } /** |