[Skiboot] [PATCH] core/device.c: Fix dt_find_compatible_node

[Alistair Popple]

> This is both less buggy and clearer.

I'm not convinced of this. It seems like it might somehow break NVLink (at least
according to git bisect) so we should probably hold off merging this until I
figure out what went wrong. Thanks.

> Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
> 
> > ---
> >   core/device.c          | 16 ++++++++++------
> >   core/test/run-device.c |  1 +
> >   2 files changed, 11 insertions(+), 6 deletions(-)
> > 
> > diff --git a/core/device.c b/core/device.c
> > index fc1db568..194eaef3 100644
> > --- a/core/device.c
> > +++ b/core/device.c
> > @@ -608,6 +608,12 @@ struct dt_node *dt_first(const struct dt_node *root)
> >   struct dt_node *dt_next(const struct dt_node *root,
> >   			const struct dt_node *prev)
> >   {
> > +	if (!prev)
> > +		prev = dt_first(root);
> > +
> > +	if (!prev)
> > +		return NULL;
> > +
> >   	/* Children? */
> >   	if (!list_empty(&prev->children))
> >   		return dt_first(prev);
> > @@ -719,10 +725,9 @@ struct dt_node *dt_find_compatible_node(struct dt_node *root,
> >   					struct dt_node *prev,
> >   					const char *compat)
> >   {
> > -	struct dt_node *node;
> > +	struct dt_node *node = prev;
> >   
> > -	node = prev ? dt_next(root, prev) : root;
> > -	for (; node; node = dt_next(root, node))
> > +	while ((node = dt_next(root, node)))
> >   		if (dt_node_is_compatible(node, compat))
> >   			return node;
> >   	return NULL;
> > @@ -964,10 +969,9 @@ struct dt_node *dt_find_compatible_node_on_chip(struct dt_node *root,
> >   						const char *compat,
> >   						uint32_t chip_id)
> >   {
> > -	struct dt_node *node;
> > +	struct dt_node *node = prev;
> >   
> > -	node = prev ? dt_next(root, prev) : root;
> > -	for (; node; node = dt_next(root, node)) {
> > +	while ((node = dt_next(root, node))) {
> >   		u32 cid = __dt_get_chip_id(node);
> >   		if (cid == chip_id &&
> >   		    dt_node_is_compatible(node, compat))
> > diff --git a/core/test/run-device.c b/core/test/run-device.c
> > index 326be3ff..6d3842e6 100644
> > --- a/core/test/run-device.c
> > +++ b/core/test/run-device.c
> > @@ -327,6 +327,7 @@ int main(void)
> >   	gc2 = dt_new(c1, "node-without-compatible");
> >   	assert(__dt_find_property(gc2, "compatible") == NULL);
> >   	assert(!dt_node_is_compatible(gc2, "any-property"));
> > +	assert(dt_find_compatible_node(gc2, NULL, "node-without-compatible") == NULL);
> >   
> >   	assert(dt_find_compatible_node(root, NULL, "generic-fake-bus") == c2);
> >   	assert(dt_find_compatible_node(root, c2, "generic-fake-bus") == NULL);
> > 
> 
>