On Tue, Sep 20, 2011 at 03:24:02PM -0500, Rob Herring wrote:
> From: Rob Herring <[email protected]>
>
> 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 <[email protected]>
> Cc: Grant Likely <[email protected]>
Looks great.
Ben, can you look at this please? Make sure I've not missed something
about how powerpc expects of_irq_find_parent() to behave.
g.
> ---
> 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;
> }
>
> /**
> --
> 1.7.5.4
>
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