ehci: Verify guest does not change the token of inflight qtd-s

This is not allowed, except for clearing active on cancellation, so don't
warn when the new token does not have its active bit set.

This unifies the cancellation path for modified qtd-s, and prepares
ehci_verify_qtd to be used ad an extra check inside
ehci_writeback_async_complete_packet().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Hans de Goede 2012-12-14 14:35:24 +01:00 committed by Gerd Hoffmann
parent c643263409
commit d066c57b1c

View file

@ -461,6 +461,7 @@ static bool ehci_verify_qtd(EHCIPacket *p, EHCIqtd *qtd)
(p->queue->async && !NLPTR_TBIT(p->qtd.next) &&
(p->qtd.next != qtd->next)) ||
(!NLPTR_TBIT(p->qtd.altnext) && (p->qtd.altnext != qtd->altnext)) ||
p->qtd.token != qtd->token ||
p->qtd.bufptr[0] != qtd->bufptr[0]) {
return false;
} else {
@ -1793,7 +1794,9 @@ static int ehci_state_fetchqtd(EHCIQueue *q)
if (p != NULL) {
if (!ehci_verify_qtd(p, &qtd)) {
ehci_cancel_queue(q);
ehci_trace_guest_bug(q->ehci, "guest updated active QH or qTD");
if (qtd.token & QTD_TOKEN_ACTIVE) {
ehci_trace_guest_bug(q->ehci, "guest updated active qTD");
}
p = NULL;
} else {
p->qtd = qtd;
@ -1802,11 +1805,6 @@ static int ehci_state_fetchqtd(EHCIQueue *q)
}
if (!(qtd.token & QTD_TOKEN_ACTIVE)) {
if (p != NULL) {
/* transfer canceled by guest (clear active) */
ehci_cancel_queue(q);
p = NULL;
}
ehci_set_state(q->ehci, q->async, EST_HORIZONTALQH);
} else if (p != NULL) {
switch (p->async) {