Re: [PATCH v2 2/2] usb: roles: get usb role switch from parent only for usb-b-connector

[Arnaud Ferraris]

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@xxxxxxxxxxxxxxx
> Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
>
> ---
> 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@xxxxxxxxxxxxx>

Cheers,
Arnaud