[PATCH 1/3] of/irq: of_irq_find_parent: check for parent equal to child
From: Rob Herring <hidden>
Date: 2011-09-20 20:24:18
Also in:
linux-devicetree, lkml
Subsystem:
open firmware and flattened device tree, the rest · Maintainers:
Rob Herring, Saravana Kannan, Linus Torvalds
From: Rob Herring <redacted> 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 <redacted> Cc: Grant Likely <redacted> --- 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 9f689f1..6a5b5e7 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; } /**
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1.7.5.4