Re: [PATCH 1/2] usb: host: xhci: Allow non-Intel usb_link_tunnel_mode reporting

[Mika Westerberg]

Hi,

On Tue, May 05, 2026 at 10:55:04AM +0200, Konrad Dybcio wrote:
> From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> 
> The Thunderbolt framework relies on the USB core to create device links
> for tunneled ports, so that the USB3 controller is only kept
> runtime-resumed for the duration of the tunneling.
> 
> Currently, retrieving that information is only possibe on Intel XHCI
> hosts, through a vendor-specific capability. Extend xhci-plat to allow
> plumbing a custom one.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> ---
>  drivers/usb/host/xhci-hub.c  | 4 ++--
>  drivers/usb/host/xhci-plat.c | 2 ++
>  drivers/usb/host/xhci-plat.h | 1 +
>  drivers/usb/host/xhci.c      | 6 +++++-
>  drivers/usb/host/xhci.h      | 5 ++++-
>  5 files changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index bacd0ddd0d09..09e5da912066 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -750,7 +750,7 @@ static int xhci_exit_test_mode(struct xhci_hcd *xhci)
>  }
>  
>  /**
> - * xhci_port_is_tunneled() - Check if USB3 connection is tunneled over USB4
> + * xhci_port_tunnel_mode() - Check if USB3 connection is tunneled over USB4
>   * @xhci: xhci host controller
>   * @port: USB3 port to be checked.
>   *
> @@ -764,7 +764,7 @@ static int xhci_exit_test_mode(struct xhci_hcd *xhci)
>   * detecting USB3 over USB4 tunnels. USB_LINK_NATIVE or USB_LINK_TUNNELED
>   * otherwise.
>   */
> -enum usb_link_tunnel_mode xhci_port_is_tunneled(struct xhci_hcd *xhci,
> +enum usb_link_tunnel_mode xhci_port_tunnel_mode(struct xhci_hcd *xhci,
>  						struct xhci_port *port)

I'm wondering if this could be:

bool xhci_port_is_tunneled()

becase if I understand correctly that's the only information we need e.g is
it going over tunnel or not.