diff options
| author | Hans de Goede <hdegoede@redhat.com> | 2012-10-24 18:14:03 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2012-10-25 09:08:09 +0200 |
| commit | e3a36bce1d0123d003855f7731494e6d6f550fcc (patch) | |
| tree | 0f89c7a809b9779ba3223614f34b5301c9ed9f86 /hw/usb | |
| parent | 44272b0f88247e2d2960c0ef19b546c206a10080 (diff) | |
ehci: Detect going in circles when filling the queue
For ctrl endpoints Windows (atleast Win7) creates circular td lists, so far
these were not a problem because we would stop filling the queue if altnext
was set. Since further patches in this patchset remove the altnext check this
does become a problem and we need detection for going in circles.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/usb')
| -rw-r--r-- | hw/usb/hcd-ehci.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c index d600f08f6b..8bd87c76d5 100644 --- a/hw/usb/hcd-ehci.c +++ b/hw/usb/hcd-ehci.c @@ -2073,7 +2073,7 @@ static int ehci_fill_queue(EHCIPacket *p) { EHCIQueue *q = p->queue; EHCIqtd qtd = p->qtd; - uint32_t qtdaddr; + uint32_t qtdaddr, start_addr = p->qtdaddr; for (;;) { if (NLPTR_TBIT(qtd.altnext) == 0) { @@ -2083,6 +2083,13 @@ static int ehci_fill_queue(EHCIPacket *p) break; } qtdaddr = qtd.next; + /* + * Detect circular td lists, Windows creates these, counting on the + * active bit going low after execution to make the queue stop. + */ + if (qtdaddr == start_addr) { + break; + } get_dwords(q->ehci, NLPTR_GET(qtdaddr), (uint32_t *) &qtd, sizeof(EHCIqtd) >> 2); ehci_trace_qtd(q, NLPTR_GET(qtdaddr), &qtd); |