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authorLinus Torvalds <torvalds@linux-foundation.org>2011-11-22 15:09:20 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-11-22 15:09:20 -0800
commitb4bbb02934e4511d9083f15c23e90703482e84ad (patch)
treeebbff074e9bab458331d1c472e2f5ee854ff8d6e /drivers
parent2db1125d51c4752ca68d1f015347b6f5b55e9fca (diff)
Revert "of/irq: of_irq_find_parent: check for parent equal to child"
This reverts commit dc9372808412edbc653a675a526c2ee6c0c14a91. As requested by Ben Herrenschmidt: "This breaks some powerpc platforms at least. The practice of having a node provide an explicit "interrupt-parent" property pointing to itself is an old trick that we've used in the past to allow a device-node to have interrupts routed to different controllers. In that case, the node also contains an interrupt-map, so the node is its own parent, the interrupt resolution hits the map, which then can route each individual interrupt to a different parent." Grant says: "Ah, nuts, yes that is broken then. Yes, please revert the commit and Rob & I will come up with a better solution. Rob, I think it can be done by explicitly checking for np == desc->interrupt_parent in of_irq_init() instead of relying on of_irq_find_parent() returning NULL." Requested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: devicetree-discuss@lists.ozlabs.org Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org> Cc: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 6d3dd3988d0..791270b8bd1 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -60,27 +60,27 @@ EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
*/
struct device_node *of_irq_find_parent(struct device_node *child)
{
- struct device_node *p, *c = child;
+ struct device_node *p;
const __be32 *parp;
- if (!of_node_get(c))
+ if (!of_node_get(child))
return NULL;
do {
- parp = of_get_property(c, "interrupt-parent", NULL);
+ parp = of_get_property(child, "interrupt-parent", NULL);
if (parp == NULL)
- p = of_get_parent(c);
+ p = of_get_parent(child);
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(c);
- c = p;
+ of_node_put(child);
+ child = p;
} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
- return (p == child) ? NULL : p;
+ return p;
}
/**