xhci: prevent bus suspend if a roothub port detected a over-current condition

commit e9fb08d617bfae5471d902112667d0eeb9dee3c4 upstream.

Suspending the bus and host controller while a port is in a over-current
condition may halt the host.
Also keep the roothub running if over-current is active.

Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200421140822.28233-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index a9c87eb..3196de2 100644 (file)
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1569,6 +1569,8 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
                }
                if ((temp & PORT_RC))
                        reset_change = true;
+               if (temp & PORT_OC)
+                       status = 1;
        }
        if (!status && !reset_change) {
                xhci_dbg(xhci, "%s: stopping port polling.\n", __func__);
@@ -1634,6 +1636,13 @@ retry:
                                 port_index);
                        goto retry;
                }
+               /* bail out if port detected a over-current condition */
+               if (t1 & PORT_OC) {
+                       bus_state->bus_suspended = 0;
+                       spin_unlock_irqrestore(&xhci->lock, flags);
+                       xhci_dbg(xhci, "Bus suspend bailout, port over-current detected\n");
+                       return -EBUSY;
+               }
                /* suspend ports in U0, or bail out for new connect changes */
                if ((t1 & PORT_PE) && (t1 & PORT_PLS_MASK) == XDEV_U0) {
                        if ((t1 & PORT_CSC) && wake_enabled) {