[PATCH 4.14 70/75] USB: ulpi: fix bus-node lookup

From: Greg Kroah-Hartman
Date: Thu Dec 07 2017 - 08:13:08 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 33c309ebc797b908029fd3a0851aefe697e9b598 upstream.

Fix bus-node lookup during registration, which ended up searching the whole
device tree depth-first starting at the parent (or grand parent) rather
than just matching on its children.

To make things worse, the parent (or grand-parent) node could end being
prematurely freed as well.

Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
Reported-by: Peter Robinson <pbrobinson@xxxxxxxxx>
Reported-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/common/ulpi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -183,9 +183,9 @@ static int ulpi_of_register(struct ulpi
/* Find a ulpi bus underneath the parent or the grandparent */
parent = ulpi->dev.parent;
if (parent->of_node)
- np = of_find_node_by_name(parent->of_node, "ulpi");
+ np = of_get_child_by_name(parent->of_node, "ulpi");
else if (parent->parent && parent->parent->of_node)
- np = of_find_node_by_name(parent->parent->of_node, "ulpi");
+ np = of_get_child_by_name(parent->parent->of_node, "ulpi");
if (!np)
return 0;