| Message ID | 20140521160931.DD7F9C4198A@trevor.secretlab.ca |
|---|---|
| State | New |
| Headers | show |
On 5/21/2014 9:09 AM, Grant Likely wrote: > On Tue, 20 May 2014 19:55:45 -0700, Frank Rowand <frowand.list@gmail.com> wrote: >> On 5/13/2014 7:58 AM, Grant Likely wrote: >> >>> Make of_find_node_by_path() handle aliases as prefixes. To make this < snip > >>> --- >> >>> drivers/of/base.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++---- >> >>> 1 file changed, 56 insertions(+), 4 deletions(-) >> >> >> >> Was this patch created against a tree that has modifications to device tree >> >> locking? >> I get a hang due to deadlock when I apply it. Patch to verify the >> cause is below. > > Ummm... I may have forgotten to enable CONFIG_LOCKDEP when testing. Try > the following fix, and can you please pass me that brown paper bag. Nononono, I need to keep the bag for my own future use :-) The following fix looks good and boots successfully on the dragonboard. -Frank > > g. > > commit 35e9c5ae6c3d0b5eb91579f397d8e1ecb95ee711 > Author: Grant Likely <grant.likely@linaro.org> > Date: Thu May 22 01:04:17 2014 +0900 > > dt: Create unlocked version of for_each_child_of_node() > > When iterating over nodes, sometimes it needs to be done when the DT > lock is already held. This patch makes an unlocked version of the > for_each_child_of_node() macro. > > Signed-off-by: Grant Likely <grant.likely@linaro.org> < snip > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/drivers/of/base.c b/drivers/of/base.c index 8900d378c07e..c05a143b6a70 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -695,6 +695,22 @@ struct device_node *of_get_next_parent(struct device_node *node) } EXPORT_SYMBOL(of_get_next_parent); +#define __for_each_child_of_node(parent, child) \ + for (child = __of_get_next_child(parent, NULL); child != NULL; \ + child = __of_get_next_child(parent, child)) +static struct device_node *__of_get_next_child(const struct device_node *node, + struct device_node *prev) +{ + struct device_node *next; + + next = prev ? prev->sibling : node->child; + for (; next; next = next->sibling) + if (of_node_get(next)) + break; + of_node_put(prev); + return next; +} + /** * of_get_next_child - Iterate a node childs * @node: parent node @@ -710,11 +726,7 @@ struct device_node *of_get_next_child(const struct device_node *node, unsigned long flags; raw_spin_lock_irqsave(&devtree_lock, flags); - next = prev ? prev->sibling : node->child; - for (; next; next = next->sibling) - if (of_node_get(next)) - break; - of_node_put(prev); + next = __of_get_next_child(node, prev); raw_spin_unlock_irqrestore(&devtree_lock, flags); return next; } @@ -780,7 +792,7 @@ static struct device_node *__of_find_node_by_path(struct device_node *parent, if (!len) return parent; - for_each_child_of_node(parent, child) { + __for_each_child_of_node(parent, child) { const char *name = strrchr(child->full_name, '/'); if (WARN(!name, "malformed device_node %s\n", child->full_name)) continue;