USB: xhci: Stop debugging polling loop when HC dies.

If the host controller card is removed from the system, stop the timer
function to debug the xHCI rings.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
index 99911e727e0b..8719a3f6851d 100644
--- a/drivers/usb/host/xhci-hcd.c
+++ b/drivers/usb/host/xhci-hcd.c
@@ -335,6 +335,12 @@ void xhci_event_ring_work(unsigned long arg)
         spin_lock_irqsave(&xhci->lock, flags);
         temp = xhci_readl(xhci, &xhci->op_regs->status);
         xhci_dbg(xhci, "op reg status = 0x%x\n", temp);
+        if (temp == 0xffffffff) {
+                xhci_dbg(xhci, "HW died, polling stopped.\n");
+                spin_unlock_irqrestore(&xhci->lock, flags);
+                return;
+        }
+
         temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
         xhci_dbg(xhci, "ir_set 0 pending = 0x%x\n", temp);
         xhci_dbg(xhci, "No-op commands handled = %d\n", xhci->noops_handled);