FAILED: patch "[PATCH] usb: roles: get usb role switch from parent only for" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 8345b1539faa49fcf9c9439c3cbd97dac6eca171
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026031615-celibate-diabolic-3dae@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8345b1539faa49fcf9c9439c3cbd97dac6eca171 Mon Sep 17 00:00:00 2001
From: Xu Yang <[email protected]>
Date: Mon, 9 Mar 2026 15:43:13 +0800
Subject: [PATCH] usb: roles: get usb role switch from parent only for
usb-b-connector

usb_role_switch_is_parent() was walking up to the parent node and checking for the "usb-role-switch" property regardless of the type of the passed fwnode. This could cause unrelated device nodes to be probed as potential role switch parent, leading to spurious matches and "-EPROBE_DEFER" being returned infinitely.

Till now only Type-B connector node will have a parent node which may present "usb-role-switch" property and register the role switch device. For Type-C connector node, its parent node will always be a Type-C chip device which will never register the role switch device. However, it may still present a non-boolean "usb-role-switch = <&usb_controller>" property for historical compatibility.

So restrict the helper to only operate on Type-B connector when attempting to get the role switch from parent node.

index b8e28ceca51e..edec139b68b5 100644
@@ -139,9 +139,14 @@ static void *usb_role_switch_match(const struct fwnode_handle *fwnode, const cha
 static struct usb_role_switch *
 usb_role_switch_is_parent(struct fwnode_handle *fwnode)
 {
-	struct fwnode_handle *parent = fwnode_get_parent(fwnode);
+	struct fwnode_handle *parent;
 	struct device *dev;
 
+	if (!fwnode_device_is_compatible(fwnode, "usb-b-connector"))
+		return NULL;
+
+	parent = fwnode_get_parent(fwnode);
+
 	if (!fwnode_property_present(parent, "usb-role-switch")) {
 		fwnode_handle_put(parent);
 		return NULL;

From: Xu Yang <[email protected]>

[ Upstream commit 8345b1539faa49fcf9c9439c3cbd97dac6eca171 ]

usb_role_switch_is_parent() was walking up to the parent node and checking for the "usb-role-switch" property regardless of the type of the passed fwnode. This could cause unrelated device nodes to be probed as potential role switch parent, leading to spurious matches and "-EPROBE_DEFER" being returned infinitely.

Till now only Type-B connector node will have a parent node which may present "usb-role-switch" property and register the role switch device. For Type-C connector node, its parent node will always be a Type-C chip device which will never register the role switch device. However, it may still present a non-boolean "usb-role-switch = <&usb_controller>" property for historical compatibility.

So restrict the helper to only operate on Type-B connector when attempting to get the role switch from parent node.

---
 drivers/usb/roles/class.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

index 917dffe9aee54..79c068c537934 100644
@@ -108,9 +108,14 @@ static void *usb_role_switch_match(struct fwnode_handle *fwnode, const char *id,
 static struct usb_role_switch *
 usb_role_switch_is_parent(struct fwnode_handle *fwnode)
 {
-	struct fwnode_handle *parent = fwnode_get_parent(fwnode);
+	struct fwnode_handle *parent;
 	struct device *dev;
 
+	if (fwnode_property_match_string(fwnode, "compatible", "usb-b-connector") < 0)
+		return NULL;
+
+	parent = fwnode_get_parent(fwnode);
+
 	if (!fwnode_property_present(parent, "usb-role-switch")) {
 		fwnode_handle_put(parent);
 		return NULL;

2.51.0