On Fri, 19 Apr 2013, Rob Herring wrote:
> On 04/19/2013 02:01 PM, Nishanth Aravamudan wrote:
> > Running 3.9-rc7-ish, tripped the following (also being seen in FC19
> > alpha) on ppc64:
> >
> > [ 117.026196] =========================================================
> > [ 117.026216] [ INFO: possible irq lock inversion dependency detected ]
> > [ 117.026238] 3.9.0-rc7+ #8 Not tainted
> > [ 117.026251] ---------------------------------------------------------
> > [ 117.026271] swapper/7/0 just changed the state of lock:
> > [ 117.026286] (&(&tp->lock)->rlock){+.-...}, at: [<c00000000064effc>]
> > .tg3_timer+0x9c/0x10f0
> > [ 117.026334] but this lock took another, SOFTIRQ-unsafe lock in the past:
> > [ 117.026353] (devtree_lock){+.+...}
Hmm. Looks like a few of the devtree functions do not disable
interrupts. Does the patch below fix the issue?
Thanks,
tglx
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 321d3ef..a218b4c 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -192,14 +192,15 @@ EXPORT_SYMBOL(of_find_property);
struct device_node *of_find_all_nodes(struct device_node *prev)
{
struct device_node *np;
+ unsigned long flags;
- raw_spin_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
np = prev ? prev->allnext : of_allnodes;
for (; np != NULL; np = np->allnext)
if (of_node_get(np))
break;
of_node_put(prev);
- raw_spin_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_all_nodes);
@@ -420,8 +421,9 @@ struct device_node *of_get_next_available_child(const
struct device_node *node,
struct device_node *prev)
{
struct device_node *next;
+ unsigned long flags;
- raw_spin_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
next = prev ? prev->sibling : node->child;
for (; next; next = next->sibling) {
if (!__of_device_is_available(next))
@@ -430,7 +432,7 @@ struct device_node *of_get_next_available_child(const
struct device_node *node,
break;
}
of_node_put(prev);
- raw_spin_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
EXPORT_SYMBOL(of_get_next_available_child);
@@ -734,13 +736,14 @@ EXPORT_SYMBOL_GPL(of_modalias_node);
struct device_node *of_find_node_by_phandle(phandle handle)
{
struct device_node *np;
+ unsigned long flags;
- raw_spin_lock(&devtree_lock);
+ raw_spin_lock_irqsave(&devtree_lock, flags);
for (np = of_allnodes; np; np = np->allnext)
if (np->phandle == handle)
break;
of_node_get(np);
- raw_spin_unlock(&devtree_lock);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_phandle);
--
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