3 files changed, 28 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index feffceb31e8a..121782e22c01 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1612,8 +1612,13 @@ static void handle_port_status(struct xhci_hcd *xhci,
                 usb_hcd_resume_root_hub(hcd);
         }
 
-        if (hcd->speed >= HCD_USB3 && (portsc & PORT_PLS_MASK) == XDEV_INACTIVE)
+        if (hcd->speed >= HCD_USB3 &&
+            (portsc & PORT_PLS_MASK) == XDEV_INACTIVE) {
+                slot_id = xhci_find_slot_id_by_port(hcd, xhci, hcd_portnum + 1);
+                if (slot_id && xhci->devs[slot_id])
+                        xhci->devs[slot_id]->flags |= VDEV_PORT_ERROR;
                 bus_state->port_remote_wakeup &= ~(1 << hcd_portnum);
+        }
 
         if ((portsc & PORT_PLC) && (portsc & PORT_PLS_MASK) == XDEV_RESUME) {
                 xhci_dbg(xhci, "port resume event for port %d\n", port_id);
@@ -1801,6 +1806,14 @@ static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
 {
         struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
         struct xhci_command *command;
+
+        /*
+         * 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
+         */
+        if (xhci->devs[slot_id]->flags & VDEV_PORT_ERROR)
+                return;
+
         command = xhci_alloc_command(xhci, false, GFP_ATOMIC);
         if (!command)
                 return;
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 20db378a6012..78a2a937dd83 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1466,6 +1466,10 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag
                         xhci_dbg(xhci, "urb submitted during PCI suspend\n");
                 return -ESHUTDOWN;
         }
+        if (xhci->devs[slot_id]->flags & VDEV_PORT_ERROR) {
+                xhci_dbg(xhci, "Can't queue urb, port error, link inactive\n");
+                return -ENODEV;
+        }
 
         if (usb_endpoint_xfer_isoc(&urb->ep->desc))
                 num_tds = urb->number_of_packets;
@@ -3754,6 +3758,7 @@ static int xhci_discover_or_reset_device(struct usb_hcd *hcd,
         }
         /* If necessary, update the number of active TTs on this root port */
         xhci_update_tt_active_eps(xhci, virt_dev, old_active_eps);
+        virt_dev->flags = 0;
         ret = 0;
 
 command_cleanup:
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 7f8b950d1a73..92e764c54154 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1010,6 +1010,15 @@ struct xhci_virt_device {
         u8                              real_port;
         struct xhci_interval_bw_table   *bw_table;
         struct xhci_tt_bw_info          *tt_info;
+        /*
+         * flags for state tracking based on events and issued commands.
+         * Software can not rely on states from output contexts because of
+         * latency between events and xHC updating output context values.
+         * See xhci 1.1 section 4.8.3 for more details
+         */
+        unsigned long                   flags;
+#define VDEV_PORT_ERROR                 BIT(0) /* Port error, link inactive */
+
         /* The current max exit latency for the enabled USB3 link states. */
         u16                             current_mel;
         /* Used for the debugfs interfaces. */