On Wed, 2 Apr 2014 05:29:53 +0000, "Li.Xiubo@xxxxxxxxxxxxx" <Li.Xiubo@xxxxxxxxxxxxx> wrote:
>
>
> > > @@ -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
>
> Yes, I will fix this.
>
>
> > and the function remains largely identical aside from moving
> > the __of_find_property() into the spinlock.
> >
>
> But, from the following codes, we can see that, if oldprop != NULL
> Meaning that we have found it, and should just do the updatation later:
> +++++++++++++++
> oldprop = of_find_property(np, newprop->name, NULL);
> if (!oldprop)
> return of_add_property(np, newprop);
> ---------------
>
>
>
> > > /* found the node */
> > > newprop->next = oldprop->next;
> > > *next = newprop;
> > > oldprop->next = np->deadprops;
> > > np->deadprops = oldprop;
> > > - found = 1;
>
> And why the 'found' flag is here is that the oldprop maybe removed
> just before the spin_lock and after of_find_property().
>
> And so use and move __of_find_property() and __of_add_property() into
> the spinlock could avoid this...
Isn't that what I said?
g.
>
>
> Thanks,
> --
>
> BRs,
> Xiubo
>
>
> > > - 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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