ehci: Fixup q->qtdaddr after cancelling an already completed packet

This avoids the q->qtdaddr == p->qtdaddr asserts we have triggering, when
a queue contains multiple completed packages when we cancel the queue.

I triggered this with windows7 + async interrupt endpoint handling (*)
+ not detecting circles in ehci_fill_queue() properly, which makes the qtd
validation in ehci_fill_queue fail, causing cancellation of the queue on every
mouse event ...

*) Which is not going upstream as it will cause loss of interrupt events on
migration.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/usb/hcd-ehci.c

@@ -189,6 +189,7 @@ static const char *ehci_mmio_names[] = {
 
 static int ehci_state_executing(EHCIQueue *q);
 static int ehci_state_writeback(EHCIQueue *q);
+static int ehci_state_advqueue(EHCIQueue *q);
 static int ehci_fill_queue(EHCIPacket *p);
 
 static const char *nr2str(const char **n, size_t len, uint32_t nr)
@@ -459,6 +460,9 @@ static void ehci_free_packet(EHCIPacket *p)
         fprintf(stderr, "EHCI: Warning packet completed but not processed\n");
         ehci_state_executing(q);
         ehci_state_writeback(q);
+        if (!(q->qh.token & QTD_TOKEN_HALT)) {
+            ehci_state_advqueue(q);
+        }
         ehci_set_state(q->ehci, q->async, state);
         /* state_writeback recurses into us with async == EHCI_ASYNC_NONE!! */
         return;