resources: allow adjust_resource() for resources with no parent

If a resource has no parent, allow its start/end to be set arbitrarily
as long as any children are still contained within the new range.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index e1d2b8ee76d5..dc8b47764443 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -722,14 +722,12 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t
 
         write_lock(&resource_lock);
 
+        if (!parent)
+                goto skip;
+
         if ((start < parent->start) || (end > parent->end))
                 goto out;
 
-        for (tmp = res->child; tmp; tmp = tmp->sibling) {
-                if ((tmp->start < start) || (tmp->end > end))
-                        goto out;
-        }
-
         if (res->sibling && (res->sibling->start <= end))
                 goto out;
 
@@ -741,6 +739,11 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t
                         goto out;
         }
 
+skip:
+        for (tmp = res->child; tmp; tmp = tmp->sibling)
+                if ((tmp->start < start) || (tmp->end > end))
+                        goto out;
+
         res->start = start;
         res->end = end;
         result = 0;