diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c index beeb3fd7b0..a9e06ef5aa 100644 --- a/hw/usb/hcd-uhci.c +++ b/hw/usb/hcd-uhci.c @@ -110,7 +110,7 @@ struct UHCIQueue { UHCIState *uhci; USBEndpoint *ep; QTAILQ_ENTRY(UHCIQueue) next; - QTAILQ_HEAD(, UHCIAsync) asyncs; + QTAILQ_HEAD(asyncs_head, UHCIAsync) asyncs; int8_t valid; }; @@ -843,15 +843,25 @@ static int uhci_handle_td(UHCIState *s, UHCIQueue *q, uint32_t qh_addr, } if (async) { - if (!async->done) - return TD_RESULT_ASYNC_CONT; if (queuing) { /* we are busy filling the queue, we are not prepared to consume completed packages then, just leave them in async state */ return TD_RESULT_ASYNC_CONT; } + if (!async->done) { + UHCI_TD last_td; + UHCIAsync *last = QTAILQ_LAST(&async->queue->asyncs, asyncs_head); + /* + * While we are waiting for the current td to complete, the guest + * may have added more tds to the queue. Note we re-read the td + * rather then caching it, as we want to see guest made changes! + */ + uhci_read_td(s, &last_td, last->td_addr); + uhci_queue_fill(async->queue, &last_td); + return TD_RESULT_ASYNC_CONT; + } uhci_async_unlink(async); goto done; }