On Tue, 1 Apr 2014 13:51:26 +0800, Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx> wrote:
> The of_update_property() is intented to update a property in a node
> and if the property does not exist, will add it.
>
> The second search of the property is possibly won't be found, that
> maybe removed by other thread just before the second search begain.
>
> Using the __of_find_property() and __of_add_property() instead and
> move them into lock operations.
>
> Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
> ---
> drivers/of/base.c | 24 +++++++++++-------------
> 1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 418a4ff9..34acb37 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -1767,7 +1767,7 @@ int of_update_property(struct device_node *np, struct property *newprop)
> {
> struct property **next, *oldprop;
> unsigned long flags;
> - int rc, found = 0;
> + int rc;
>
> rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
> if (rc)
> @@ -1776,25 +1776,26 @@ int of_update_property(struct device_node *np, struct property *newprop)
> if (!newprop->name)
> return -EINVAL;
>
> - oldprop = of_find_property(np, newprop->name, NULL);
> - if (!oldprop)
> - return of_add_property(np, newprop);
> -
> raw_spin_lock_irqsave(&devtree_lock, flags);
> - next = &np->properties;
> - while (*next) {
> + oldprop = __of_find_property(np, newprop->name, NULL);
> + if (!oldprop) {
> + /* add the node */
> + rc = __of_add_property(np, newprop);
> + } else {
if you changed this line to:
} else while (*next) {
then most of the other changes go away. You don't need the separate
while loop and the function remains largely identical aside from moving
the __of_find_property() into the spinlock.
> + next = &np->properties;
> + while (*next && *next != oldprop)
> + next = &(*next)->next;
> +
> if (*next == oldprop) {
> /* found the node */
> newprop->next = oldprop->next;
> *next = newprop;
> oldprop->next = np->deadprops;
> np->deadprops = oldprop;
> - found = 1;
> - break;
> }
> - next = &(*next)->next;
> }
> raw_spin_unlock_irqrestore(&devtree_lock, flags);
> +
> if (rc)
> return rc;
>
> @@ -1803,9 +1804,6 @@ int of_update_property(struct device_node *np, struct property *newprop)
> sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
> __of_add_property_sysfs(np, newprop);
>
> - if (!found)
> - return -ENODEV;
> -
> return 0;
> }
>
> --
> 1.8.4
>
>
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