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.

Fixes: 6fadd72943b8 ("usb: roles: get usb-role-switch from parent")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

---
Changes in v2:
 - new patch
---
 drivers/usb/roles/class.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index b8e28ceca51e..edec139b68b5 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -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;
-- 
2.34.1

From: Frank Li (AI-BOT) <frank.li@nxp.com>

> if (!fwnode_device_is_compatible(fwnode, "usb-b-connector"))
> 		return NULL;

AI: Nit: inconsistent indentation. Should use a single tab, not two spaces.
Use '\t' for the return statement to match kernel style.

> 	parent = fwnode_get_parent(fwnode);
>
> 	if (!fwnode_property_present(parent, "usb-role-switch")) {

AI: Missing NULL check on parent before passing to fwnode_property_present().
If fwnode_get_parent() returns NULL, the next call will dereference it.
Add: if (!parent) return NULL;

Frank

Hi Frank,

On Mon, Mar 09, 2026 at 03:48:59PM -0400, Frank Li wrote:
> From: Frank Li (AI-BOT) <frank.li@nxp.com>
> 
> > if (!fwnode_device_is_compatible(fwnode, "usb-b-connector"))
> > 		return NULL;
> 
> AI: Nit: inconsistent indentation. Should use a single tab, not two spaces.
> Use '\t' for the return statement to match kernel style.
> 
> > 	parent = fwnode_get_parent(fwnode);
> >
> > 	if (!fwnode_property_present(parent, "usb-role-switch")) {
> 
> AI: Missing NULL check on parent before passing to fwnode_property_present().
> If fwnode_get_parent() returns NULL, the next call will dereference it.
> Add: if (!parent) return NULL;

Ignore this!

Both above AI reported issues are false-alarm. Please refine the AI-BOT.
And the message he sent didn't reach to me (I'm not in --to list). So the
issue may not be resolved timely.

Thanks,
Xu Yang

Le 09/03/2026 à 08:43, Xu Yang a écrit :
> 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.
> 
> Fixes: 6fadd72943b8 ("usb: roles: get usb-role-switch from parent")
> Cc: stable@vger.kernel.org
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> 
> ---
> Changes in v2:
>   - new patch
> ---
>   drivers/usb/roles/class.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index b8e28ceca51e..edec139b68b5 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -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;

Tested-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>

Cheers,
Arnaud