diff options
| author | Stephen Warren <swarren@nvidia.com> | 2013-02-11 21:15:32 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2013-04-04 22:09:05 (GMT) |
| commit | 10188d8cc7d3010388e5d0259fe26670228139d3 (patch) | |
| tree | 8d24e2372ae55e5100832a0da113df555eec6537 /drivers/of | |
| parent | d0b25b2988e9b836b81a1a80d1fedf044b22b65e (diff) | |
| download | linux-fsl-qoriq-10188d8cc7d3010388e5d0259fe26670228139d3.tar.xz | |
of: fix recursive locking in of_get_next_available_child()
of_get_next_available_child() acquires devtree_lock, then calls
of_device_is_available() which calls of_get_property() which calls
of_find_property() which tries to re-acquire devtree_lock, thus causing
deadlock.
To avoid this, create a new __of_device_is_available() which calls
__of_get_property() instead, which calls __of_find_property(), which
does not take the lock,. Update of_get_next_available_child() to call
the new __of_device_is_available() since it already owns the lock.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/base.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 662e009..ec2fd1f 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -307,19 +307,19 @@ int of_machine_is_compatible(const char *compat) EXPORT_SYMBOL(of_machine_is_compatible); /** - * of_device_is_available - check if a device is available for use + * __of_device_is_available - check if a device is available for use * - * @device: Node to check for availability + * @device: Node to check for availability, with locks already held * * Returns 1 if the status property is absent or set to "okay" or "ok", * 0 otherwise */ -int of_device_is_available(const struct device_node *device) +static int __of_device_is_available(const struct device_node *device) { const char *status; int statlen; - status = of_get_property(device, "status", &statlen); + status = __of_get_property(device, "status", &statlen); if (status == NULL) return 1; @@ -330,6 +330,26 @@ int of_device_is_available(const struct device_node *device) return 0; } + +/** + * of_device_is_available - check if a device is available for use + * + * @device: Node to check for availability + * + * Returns 1 if the status property is absent or set to "okay" or "ok", + * 0 otherwise + */ +int of_device_is_available(const struct device_node *device) +{ + unsigned long flags; + int res; + + raw_spin_lock_irqsave(&devtree_lock, flags); + res = __of_device_is_available(device); + raw_spin_unlock_irqrestore(&devtree_lock, flags); + return res; + +} EXPORT_SYMBOL(of_device_is_available); /** @@ -421,7 +441,7 @@ struct device_node *of_get_next_available_child(const struct device_node *node, raw_spin_lock(&devtree_lock); next = prev ? prev->sibling : node->child; for (; next; next = next->sibling) { - if (!of_device_is_available(next)) + if (!__of_device_is_available(next)) continue; if (of_node_get(next)) break; |