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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
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drivers/of/irq.c
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drivers/of/irq.c
···
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*/
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struct device_node *of_irq_find_parent(struct device_node *child)
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{
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-
struct device_node *p;
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struct device_node *p, *c = child;
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const __be32 *parp;
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if (!of_node_get(child))
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if (!of_node_get(c))
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return NULL;
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do {
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parp = of_get_property(child, "interrupt-parent", NULL);
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parp = of_get_property(c, "interrupt-parent", NULL);
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if (parp == NULL)
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p = of_get_parent(child);
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p = of_get_parent(c);
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else {
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if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
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p = of_node_get(of_irq_dflt_pic);
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else
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p = of_find_node_by_phandle(be32_to_cpup(parp));
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}
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of_node_put(child);
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child = p;
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of_node_put(c);
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c = p;
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} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
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-
return p;
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return (p == child) ? NULL : p;
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}
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/**