Merge remote-tracking branch 'remotes/kraxel/tags/usb-20180703-pull-request' into staging

usb: bugfixes for ehci and xhci.

# gpg: Signature made Tue 03 Jul 2018 09:26:20 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/usb-20180703-pull-request:
  xhci: fix guest-triggerable assert
  ehci: Don't fetch a NULL current qtd but advance the queue instead.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/usb/hcd-ehci.c

@@ -1672,7 +1672,8 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
         ehci_set_state(ehci, async, EST_HORIZONTALQH);
 
     } else if ((q->qh.token & QTD_TOKEN_ACTIVE) &&
-               (NLPTR_TBIT(q->qh.current_qtd) == 0)) {
+               (NLPTR_TBIT(q->qh.current_qtd) == 0) &&
+               (q->qh.current_qtd != 0)) {
         q->qtdaddr = q->qh.current_qtd;
         ehci_set_state(ehci, async, EST_FETCHQTD);
 

hw/usb/hcd-xhci.c

@@ -1954,7 +1954,12 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)
         for (i = 0; i < length; i++) {
             TRBType type;
             type = xhci_ring_fetch(xhci, ring, &xfer->trbs[i], NULL);
-            assert(type);
+            if (!type) {
+                xhci_die(xhci);
+                xhci_ep_free_xfer(xfer);
+                epctx->kick_active--;
+                return;
+            }
         }
         xfer->streamid = streamid;