Re: [PATCH 1/3] of/irq: of_irq_find_parent: check for parent equal to child
From: Grant Likely <hidden>
Date: 2011-09-20 21:01:07
Also in:
linux-arm-kernel, lkml
On Tue, Sep 20, 2011 at 03:24:02PM -0500, Rob Herring wrote:
From: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org> 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-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org> Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
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.
quoted hunk ↗ jump to hunk
--- 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