From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
To: Konrad Dybcio <konradybcio@kernel.org>
Cc: Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Mathias Nyman <mathias.nyman@intel.com>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"usb4-upstream@oss.qualcomm.com" <usb4-upstream@oss.qualcomm.com>,
Raghavendra Thoorpu <rthoorpu@qti.qualcomm.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Sven Peter <sven@kernel.org>,
Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Subject: Re: [PATCH v3 3/4] usb: xhci: Allow custom op for usb_link_tunnel_mode reporting
Date: Sat, 5 Sep 2026 00:29:01 +0000 [thread overview]
Message-ID: <aptiQnAoeiHW6Dmy@vbox> (raw)
In-Reply-To: <20260901-topic-dwc3_tunneling_state-v3-3-22fdced8de55@oss.qualcomm.com>
On Tue, Sep 01, 2026, Konrad Dybcio wrote:
> From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
>
> 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@oss.qualcomm.com>
> ---
> drivers/usb/host/xhci-hub.c | 13 +++++++++----
> drivers/usb/host/xhci-plat.c | 2 ++
> drivers/usb/host/xhci-plat.h | 1 +
> drivers/usb/host/xhci.c | 3 ++-
> drivers/usb/host/xhci.h | 5 ++++-
> 5 files changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 80f07bd5081d..c585e4d02d84 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -749,7 +749,7 @@ 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.
> *
> @@ -763,7 +763,7 @@ 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)
> {
> struct usb_hcd *hcd;
> @@ -782,8 +782,13 @@ enum usb_link_tunnel_mode xhci_port_is_tunneled(struct xhci_hcd *xhci,
> /* Fall back to the legacy Intel-specific ext_cap */
> hcd = xhci_to_hcd(xhci);
> if (!dev_is_pci(hcd->self.controller) ||
> - to_pci_dev(hcd->self.controller)->vendor != PCI_VENDOR_ID_INTEL)
> - return USB_LINK_UNKNOWN;
> + to_pci_dev(hcd->self.controller)->vendor != PCI_VENDOR_ID_INTEL) {
> + /* Last chance - if the controller has a custom tunnel_mode op, try that */
> + if (xhci->tunnel_mode)
> + return xhci->tunnel_mode(xhci_to_hcd(xhci), port->hcd_portnum);
> + else
> + return USB_LINK_UNKNOWN;
> + }
>
> base = &xhci->cap_regs->hc_capbase;
> offset = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_INTEL_SPR_SHADOW);
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 6fd595f81a30..c19bc5d7a7b5 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -244,6 +244,8 @@ int xhci_plat_probe(struct platform_device *pdev, struct device *sysdev, const s
> priv = hcd_to_xhci_priv(hcd);
> /* Just copy data for now */
> *priv = *priv_match;
> +
> + xhci->tunnel_mode = priv->tunnel_mode;
> }
>
> device_set_wakeup_capable(&pdev->dev, true);
> diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
> index 00751d851831..c5042766a486 100644
> --- a/drivers/usb/host/xhci-plat.h
> +++ b/drivers/usb/host/xhci-plat.h
> @@ -22,6 +22,7 @@ struct xhci_plat_priv {
> int (*suspend_quirk)(struct usb_hcd *);
> int (*resume_quirk)(struct usb_hcd *);
> int (*post_resume_quirk)(struct usb_hcd *);
> + enum usb_link_tunnel_mode (*tunnel_mode)(struct usb_hcd *hcd, int portnum);
> };
>
> #define hcd_to_xhci_priv(h) ((struct xhci_plat_priv *)hcd_to_xhci(h)->priv)
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 5fb78613a993..a7e3c46937fa 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -4762,7 +4762,8 @@ static int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
> if (hcd->speed >= HCD_USB3 && !udev->parent->parent) {
> port = xhci->usb3_rhub.ports[udev->portnum - 1];
>
> - udev->tunnel_mode = xhci_port_is_tunneled(xhci, port);
> + udev->tunnel_mode = xhci_port_tunnel_mode(xhci, port);
> +
> if (udev->tunnel_mode == USB_LINK_UNKNOWN)
> dev_dbg(&udev->dev, "link tunnel state unknown\n");
> else if (udev->tunnel_mode == USB_LINK_TUNNELED)
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 480fcbac4525..2b5c0b304c6b 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1675,6 +1675,9 @@ struct xhci_hcd {
> struct list_head regset_list;
>
> void *dbc;
> +
> + enum usb_link_tunnel_mode (*tunnel_mode)(struct usb_hcd *hcd, int portnum);
> +
> /* platform-specific data -- must come last */
> unsigned long priv[] __aligned(sizeof(s64));
> };
> @@ -1981,7 +1984,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
> int xhci_hub_status_data(struct usb_hcd *hcd, char *buf);
> int xhci_find_raw_port_number(struct usb_hcd *hcd, int port1);
> struct xhci_hub *xhci_get_rhub(struct usb_hcd *hcd);
> -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);
> void xhci_hc_died(struct xhci_hcd *xhci);
>
>
> --
> 2.55.0
>
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Thanks,
Thinh
next prev parent reply other threads:[~2026-09-05 0:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 10:05 [PATCH v3 0/4] DWC3 link tunneling state reporting Konrad Dybcio
2026-09-01 10:05 ` [PATCH v3 1/4] usb: xhci: debugfs: Expose the USB3 tunneling ext_cap register value Konrad Dybcio
2026-09-05 0:26 ` Thinh Nguyen
2026-09-01 10:05 ` [PATCH v3 2/4] usb: xhci: Honor PORTSC.TM if valid Konrad Dybcio
2026-09-05 0:27 ` Thinh Nguyen
2026-09-01 10:05 ` [PATCH v3 3/4] usb: xhci: Allow custom op for usb_link_tunnel_mode reporting Konrad Dybcio
2026-09-05 0:29 ` Thinh Nguyen [this message]
2026-09-01 10:05 ` [PATCH v3 4/4] usb: dwc3: Notify XHCI core of tunneled status Konrad Dybcio
2026-09-05 0:30 ` Thinh Nguyen
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