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SubjectRe: [PATCH 05.1/16] of:overlay: missing name, phandle, linux,phandle in new nodes
On Wed, Oct 10, 2018 at 1:49 AM Frank Rowand <frowand.list@gmail.com> wrote:
>
> On 10/09/18 23:04, frowand.list@gmail.com wrote:
> > From: Frank Rowand <frank.rowand@sony.com>
> >
> >
> > "of: overlay: use prop add changeset entry for property in new nodes"
> > fixed a problem where an 'update property' changeset entry was
> > created for properties contained in nodes added by a changeset.
> > The fix was to use an 'add property' changeset entry.
> >
> > This exposed more bugs in the apply overlay code. The properties
> > 'name', 'phandle', and 'linux,phandle' were filtered out by
> > add_changeset_property() as special properties. Change the filter
> > to be only for existing nodes, not newly added nodes.
> >
> > The second bug is that the 'name' property does not exist in the
> > newest FDT version, and has to be constructed from the node's
> > full_name. Construct an 'add property' changeset entry for
> > newly added nodes.
> >
> > Signed-off-by: Frank Rowand <frank.rowand@sony.com>
> > ---
> >
> >
> > Hi Alan,
> >
> > Thanks for reporting the problem with missing node names.
> >
> > I was able to replicate the problem, and have created this preliminary
> > version of a patch to fix the problem.
> >
> > I have not extensively reviewed the patch yet, but would appreciate
> > if you can confirm this fixes your problem.
> >
> > I created this patch as patch 17 of the series, but have also
> > applied it as patch 05.1, immediately after patch 05/16, and
> > built the kernel, booted, and verified name and phandle for
> > one of the nodes in a unittest overlay for both cases. So
> > minimal testing so far on my part.
> >
> > I have not verified whether the series builds and boots after
> > each of patches 06..16 if this patch is applied as patch 05.1.
> >
> > There is definitely more work needed for me to complete this
> > patch because it allocates some more memory, but does not yet
> > free it when the overlay is released.
> >
> > -Frank
> >
> >
> > drivers/of/overlay.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++----
> > 1 file changed, 67 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
> > index 0b0904f44bc7..9746cea2aa91 100644
> > --- a/drivers/of/overlay.c
> > +++ b/drivers/of/overlay.c
> > @@ -301,10 +301,11 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
> > struct property *new_prop = NULL, *prop;
> > int ret = 0;
> >
> > - if (!of_prop_cmp(overlay_prop->name, "name") ||
> > - !of_prop_cmp(overlay_prop->name, "phandle") ||
> > - !of_prop_cmp(overlay_prop->name, "linux,phandle"))
> > - return 0;
> > + if (target->in_livetree)
> > + if (!of_prop_cmp(overlay_prop->name, "name") ||
> > + !of_prop_cmp(overlay_prop->name, "phandle") ||
> > + !of_prop_cmp(overlay_prop->name, "linux,phandle"))
> > + return 0;
>
> This is a big hammer patch.
>
> Nobody should waste time reviewing this patch.

I wasn't clear if you still could use the testing so I did re-run my
test. This patch adds back some of the missing properties, but the
the kobject names aren't set as dev_name() returns NULL:

* without this patch some of_node properties don't show up in sysfs:
root@arria10:~# ls
/sys/bus/platform/drivers/altera_freeze_br/ff200450.\<NULL\>/of_node
clocks compatible interrupt-parent interrupts reg

* with this patch, the of_node properties phandle and name are back:
root@arria10:~# ls
/sys/bus/platform/drivers/altera_freeze_br/ff200450.\<NULL\>/of_node
clocks compatible interrupt-parent interrupts
name phandle reg

root@arria10:~# cat
/sys/bus/platform/drivers/altera_freeze_br/ff200450.\<NULL\>/of_node/name
freeze_controllerroot@arria10:~# ("freeze_controller" w/o the \n so
the name is correct)

* with or without the patch I see the behavior I reported yesterday,
kobj names are NULL.
root@arria10:~# ls /sys/bus/platform/drivers/altera_freeze_br/
bind ff200450.<NULL> uevent unbind

root@arria10:~# ls /sys/bus/platform/drivers/altera_gpio/
bind ff200010.<NULL> ff200020.<NULL> ff200030.<NULL>
uevent unbind

Alan

Alan

>
> The following part should not be needed (though the above section might have
> to become _slightly_ more complex).
>
> -Frank
> >
> > if (target->in_livetree)
> > prop = of_find_property(target->np, overlay_prop->name, NULL);
> > @@ -443,10 +444,13 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs,
> > struct target *target, const struct device_node *overlay_node)
> > {
> > struct device_node *child;
> > - struct property *prop;
> > + struct property *prop, *name_prop;
> > + bool has_name = false;
> > int ret;
> >
> > for_each_property_of_node(overlay_node, prop) {
> > + if (!strcmp(prop->name, "name"))
> > + has_name = true;
> > ret = add_changeset_property(ovcs, target, prop, 0);
> > if (ret) {
> > pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
> > @@ -455,6 +459,57 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs,
> > }
> > }
> >
> > + /*
> > + * With FDT version 0x10 we may not have the name property,
> > + * recreate it here from the unit name if absent
> > + */
> > +
> > + if (!has_name) {
> > + const char *p = target->np->full_name, *ps = p, *pa = NULL;
> > + int len;
> > +
> > + /*
> > + * zzz
> > + * TODO: stash name_prop on a list in ovcs, to be freed
> > + * after overlay removed
> > + */
> > +
> > + while (*p) {
> > + if ((*p) == '@')
> > + pa = p;
> > + else if ((*p) == '/')
> > + ps = p + 1;
> > + p++;
> > + }
> > +
> > + if (pa < ps)
> > + pa = p;
> > + len = (pa - ps) + 1;
> > +
> > + name_prop = kmalloc(sizeof(*name_prop), GFP_KERNEL);
> > + if (!name_prop)
> > + return -ENOMEM;
> > +
> > + name_prop->name = kstrdup("name", GFP_KERNEL);
> > + name_prop->value = kmalloc(len, GFP_KERNEL);
> > + if (!name_prop->name || !name_prop->value) {
> > + ret = -ENOMEM;
> > + goto err_free_name_prop;
> > + }
> > +
> > + memcpy(name_prop->value, ps, len - 1);
> > + ((char *)name_prop->value)[len - 1] = 0;
> > +
> > + name_prop->length = strlen(name_prop->value) + 1;
> > +
> > + ret = add_changeset_property(ovcs, target, name_prop, 0);
> > + if (ret) {
> > + pr_debug("Failed to apply name_prop @%pOF/%s, err=%d\n",
> > + target->np, name_prop->name, ret);
> > + goto err_free_name_prop;
> > + }
> > + }
> > +
> > for_each_child_of_node(overlay_node, child) {
> > ret = add_changeset_node(ovcs, target, child);
> > if (ret) {
> > @@ -466,6 +521,13 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs,
> > }
> >
> > return 0;
> > +
> > +err_free_name_prop:
> > + kfree(name_prop->name);
> > + kfree(name_prop->value);
> > + kfree(name_prop);
> > + return ret;
> > +
> > }
> >
> > /*
> >
>

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