Re: [PATCH] of: fix recursive locking in of_get_next_available_child()

From: Grant Likely
Date: Mon Feb 11 2013 - 17:39:18 EST


On Mon, 11 Feb 2013 14:15:32 -0700, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote:
> From: Stephen Warren <swarren@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>

Thanks for looking at this Stephen. I ended up applying my version of
this patch though just because it was more convenient to do so. It was
pretty much identical anyway.

g.
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