Re: [PATCH] of: Fix locking when calling of_get_next_available_child()

Grant Likely
2013-02-11T22:31:11Z

On Mon, Feb 11, 2013 at 10:27 PM, Rob Herring <robherring2@gmail.com> wrote:
> On 02/11/2013 04:19 PM, Grant Likely wrote:
>> of_get_next_available_child() obtains the devtree_lock and then calls
>> of_device_is_available() which also attempts to claim the lock. This is
>> obviously incorrect and causes a deadlock on boot. Fix issue by adding
>> an variant of of_device_is_available() which doesn't obtain the lock.
>>
>> Cc: Stephen Warren <swarren@wwwdotorg.org>
>> Cc: Rob Herring <robherring2@gmail.com>
>> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
>> ---
>> drivers/of/base.c | 15 +++++++++++++--
>> 1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index e8d65af..4af74b7 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -297,7 +297,7 @@ EXPORT_SYMBOL(of_machine_is_compatible);
>> * 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)
>> +int __of_device_is_available(const struct device_node *device)
>> {
>> const char *status;
>> int statlen;
>> @@ -313,6 +313,17 @@ int of_device_is_available(const struct device_node *device)
>>
>> return 0;
>> }
>> +
>> +int of_device_is_available(const struct device_node *device)
>
> Stephen's version wins because he preserved the documentation. :)

Pish. He just cut and paste the documentation so now we have 2 copies.
My version wins because it is already in my tree. So ptfff!

:-)

g.