From dbbaf9e5f42261811cdb2bb0dde6fa201eebe263 Mon Sep 17 00:00:00 2001 From: "Chia-Lin Kao (AceLan)" Date: Thu, 19 Mar 2026 10:57:17 +0800 Subject: [PATCH 1/3] xhci: restrict VDEV_PORT_ERROR to USB3 ports in handle_port_status() Commit b69dfcab6894 ("xhci: fix stale flag preventig URBs after link state error is cleared") removed the hcd->speed >= HCD_USB3 guard when setting the VDEV_PORT_ERROR flag for ports with link state XDEV_INACTIVE (PLS=6). Per the xHCI specification, PLS value 6 (SS.Inactive) is only defined for USB 3.0 ports. For USB 2.0 ports, this value is reserved and may be read transiently, especially on ports behind Thunderbolt 4 docks with Realtek USB 2.0 hubs. Without the USB3 guard, these transient reads cause VDEV_PORT_ERROR to be incorrectly set on USB 2.0 devices, blocking URB queueing and preventing device enumeration. Restore the hcd->speed >= HCD_USB3 check on the VDEV_PORT_ERROR set path, while preserving the other improvements from b69dfcab6894: - The PORT_RESET guard preventing flag set during active reset - The PORT_RC path to clear the flag when reset completes - The vdev->flags = 0 clearing in xhci_discover_or_reset_device() BugLink: https://bugs.launchpad.net/bugs/2144606 Fixes: b69dfcab6894 ("xhci: fix stale flag preventig URBs after link state error is cleared") Cc: stable@vger.kernel.org Signed-off-by: Chia-Lin Kao (AceLan) --- drivers/usb/host/xhci-ring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index c94f22d8ea20c..bca44bc13ce75 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2046,7 +2046,8 @@ static void handle_port_status(struct xhci_hcd *xhci, union xhci_trb *event) usb_hcd_resume_root_hub(hcd); } - if (vdev && (portsc & PORT_PLS_MASK) == XDEV_INACTIVE) { + if (hcd->speed >= HCD_USB3 && vdev && + (portsc & PORT_PLS_MASK) == XDEV_INACTIVE) { if (!(portsc & PORT_RESET)) vdev->flags |= VDEV_PORT_ERROR; } else if (vdev && portsc & PORT_RC) { -- 2.53.0