From 042aad8d0db6607ac9789fc43b6221909bd6a3bc Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Thu, 6 Aug 2026 17:21:00 +0300 Subject: [PATCH] xhci: prevent endpoint recovery after roothub disconnect Prevent transfer retry and endpoint recovery if the device or its parent disconnected from the roothub. Just like link error case. There is a suspicion some xHC controllers may stop processing endpoint related commands after the last USB device disconnects from the host. Disconnect often causes transaction errors, xhci driver tries to (soft) reset and restart the endpoint to recover it. Hub driver again will cancel all pending URBs once disconnect is detected, stopping the endpoint right after (soft) reset restarted it. xHC controller sometimes fail to complete the stop endpoint command, leading to driver timing out, and tearing down xhci Prevent extra endpoint (soft) reset after xhci driver is aware of the parent roothub port disconnect. Tested-by: Xu Rao Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260806142113.2436238-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 12 ++++++++---- drivers/usb/host/xhci.h | 1 + 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 544749b607a4..656ed6470e4a 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -986,14 +986,16 @@ static int xhci_handle_halted_endpoint(struct xhci_hcd *xhci, struct xhci_td *td, enum xhci_ep_reset_type reset_type) { + struct xhci_port *rhub_port = ep->vdev->rhub_port; unsigned int slot_id = ep->vdev->slot_id; int err; /* - * Avoid resetting endpoint if link is inactive. Can cause host hang. - * Device will be reset soon to recover the link so don't do anything + * Avoid resetting endpoint if link is inactive or device disonnected. + * Can cause host hang. + * Device will be reset to recover an inactive link, so don't do anything */ - if (ep->vdev->rhub_port->link_inactive) + if (rhub_port->link_inactive || !rhub_port->connected) return -ENODEV; /* add td to cancelled list and let reset ep handler take care of it */ @@ -2053,8 +2055,10 @@ static void handle_port_status(struct xhci_hcd *xhci, union xhci_trb *event) * Tag broken links to avoid retries while hub driver sorts it out. * Link status is not relible while port is in reset. */ - if (!(portsc & PORT_RESET)) + if (!(portsc & PORT_RESET)) { port->link_inactive = (pls == XDEV_INACTIVE); + port->connected = !!(portsc & PORT_CONNECT); + } if ((portsc & PORT_PLC) && (portsc & PORT_PLS_MASK) == XDEV_RESUME) { xhci_dbg(xhci, "port resume event for port %d\n", port_id); diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 9b6c7aeb1dca..0cc9edfd86f3 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1478,6 +1478,7 @@ struct xhci_port { struct xhci_hub *rhub; struct xhci_port_cap *port_cap; unsigned int link_inactive:1; + unsigned int connected:1; unsigned int lpm_incapable:1; unsigned long resume_timestamp; bool rexit_active;