1 files changed, 9 insertions, 0 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index ca7ed5158cff..35fe105d581e 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1132,6 +1132,15 @@ struct resource * __request_region(struct resource *parent,
                 conflict = __request_resource(parent, res);
                 if (!conflict)
                         break;
+                /*
+                 * mm/hmm.c reserves physical addresses which then
+                 * become unavailable to other users.  Conflicts are
+                 * not expected.  Warn to aid debugging if encountered.
+                 */
+                if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
+                        pr_warn("Unaddressable device %s %pR conflicts with %pR",
+                                conflict->name, conflict, res);
+                }
                 if (conflict != parent) {
                         if (!(conflict->flags & IORESOURCE_BUSY)) {
                                 parent = conflict;