xhci: Avoid BUG() in interrupt context

commit 68e41c5d032668e2905404afbef75bc58be179d6 upstream.

Change the BUGs in xhci_find_new_dequeue_state() to WARN_ONs, to avoid
bringing down the box if one of them is hit

This patch should be queued for stable kernels back to 2.6.31.

Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 632a7b60ed106250961bcc95c31f51b65d99082a..6ead609e543fd4848941d33dd840d0976683b36a 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -392,8 +392,11 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
        state->new_deq_seg = find_trb_seg(cur_td->start_seg,
                        dev->eps[ep_index].stopped_trb,
                        &state->new_cycle_state);
-       if (!state->new_deq_seg)
-               BUG();
+       if (!state->new_deq_seg) {
+               WARN_ON(1);
+               return;
+       }
+
        /* Dig out the cycle state saved by the xHC during the stop ep cmd */
        xhci_dbg(xhci, "Finding endpoint context\n");
        ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
@@ -404,8 +407,10 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
        state->new_deq_seg = find_trb_seg(state->new_deq_seg,
                        state->new_deq_ptr,
                        &state->new_cycle_state);
-       if (!state->new_deq_seg)
-               BUG();
+       if (!state->new_deq_seg) {
+               WARN_ON(1);
+               return;
+       }
 
        trb = &state->new_deq_ptr->generic;
        if ((trb->field[3] & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK) &&