xhci: Better debugging for critical host errors.

When a host controller gives a bad event TRB, we should print out the
contents of the TRB as a warning so that users don't have to recompile
their kernel to get information about what went wrong.  Also, print out
the event ring if they have xHCI debugging turned on, since previous
events can often explain what happened before the bad TRB occurred.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index f34a268c6ccded68963b073c3b3eaca11e1b5ec1..b0a85459652e0dd74cd83307b2213290837a2391 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1933,6 +1933,15 @@ static int handle_tx_event(struct xhci_hcd *xhci,
        xdev = xhci->devs[slot_id];
        if (!xdev) {
                xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
+               xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
+                        xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
+                                xhci->event_ring->dequeue),
+                        lower_32_bits(le64_to_cpu(event->buffer)),
+                        upper_32_bits(le64_to_cpu(event->buffer)),
+                        le32_to_cpu(event->transfer_len),
+                        le32_to_cpu(event->flags));
+               xhci_dbg(xhci, "Event ring:\n");
+               xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
                return -ENODEV;
        }
 
@@ -1946,6 +1955,15 @@ static int handle_tx_event(struct xhci_hcd *xhci,
            EP_STATE_DISABLED) {
                xhci_err(xhci, "ERROR Transfer event for disabled endpoint "
                                "or incorrect stream ring\n");
+               xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
+                        xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
+                                xhci->event_ring->dequeue),
+                        lower_32_bits(le64_to_cpu(event->buffer)),
+                        upper_32_bits(le64_to_cpu(event->buffer)),
+                        le32_to_cpu(event->transfer_len),
+                        le32_to_cpu(event->flags));
+               xhci_dbg(xhci, "Event ring:\n");
+               xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
                return -ENODEV;
        }