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ehci: Don't set seen to 0 when removing unseen queue-heads

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When removing unseen queue-heads from the async queue list, we should not
set the seen flag to 0, as this may cause them to be removed by
ehci_queues_rip_unused() during the next call to ehci_advance_async_state()
if the timer is late or running at a low frequency.

Note:
1) This *may* have caused the instant unlink / relinks described in commit
   9bc3a3a216e2689bfcdd36c3e079333bbdbf3ba0

2) Rather then putting more if-s inside ehci_queues_rip_unused, this patch
   instead introduces a new ehci_queues_rip_unseen function.

3) This patch also makes it save to call ehci_queues_rip_unseen() multiple
   times, which gets used in the folluw up patch titled:
   "ehci: Walk async schedule before and after migration"

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 2012-09-12 15:08:32 +02:00 committed by Gerd Hoffmann
parent 56ab2ad177
commit 8f5457eb04
1 changed files with 18 additions and 6 deletions
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24
hw/usb/hcd-ehci.c
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@ -848,10 +848,10 @@ static EHCIQueue *ehci_find_queue_by_qh(EHCIState *ehci, uint32_t addr,
return NULL;
}
static void ehci_queues_rip_unused(EHCIState *ehci, int async, int flush)
static void ehci_queues_rip_unused(EHCIState *ehci, int async)
{
EHCIQueueHead *head = async ? &ehci->aqueues : &ehci->pqueues;
const char *warn = (async && !flush) ? "guest unlinked busy QH" : NULL;
const char *warn = async ? "guest unlinked busy QH" : NULL;
uint64_t maxage = FRAME_TIMER_NS * ehci->maxframes * 4;
EHCIQueue *q, *tmp;
@ -861,13 +861,25 @@ static void ehci_queues_rip_unused(EHCIState *ehci, int async, int flush)
q->ts = ehci->last_run_ns;
continue;
}
if (!flush && ehci->last_run_ns < q->ts + maxage) {
if (ehci->last_run_ns < q->ts + maxage) {
continue;
}
ehci_free_queue(q, warn);
}
}
static void ehci_queues_rip_unseen(EHCIState *ehci, int async)
{
EHCIQueueHead *head = async ? &ehci->aqueues : &ehci->pqueues;
EHCIQueue *q, *tmp;
QTAILQ_FOREACH_SAFE(q, head, next, tmp) {
if (!q->seen) {
ehci_free_queue(q, NULL);
}
}
}
static void ehci_queues_rip_device(EHCIState *ehci, USBDevice *dev, int async)
{
EHCIQueueHead *head = async ? &ehci->aqueues : &ehci->pqueues;
@ -1700,7 +1712,7 @@ static int ehci_state_waitlisthead(EHCIState *ehci, int async)
ehci_set_usbsts(ehci, USBSTS_REC);
}
ehci_queues_rip_unused(ehci, async, 0);
ehci_queues_rip_unused(ehci, async);
/* Find the head of the list (4.9.1.1) */
for(i = 0; i < MAX_QH; i++) {
@ -2332,7 +2344,7 @@ static void ehci_advance_async_state(EHCIState *ehci)
*/
if (ehci->usbcmd & USBCMD_IAAD) {
/* Remove all unseen qhs from the async qhs queue */
ehci_queues_rip_unused(ehci, async, 1);
ehci_queues_rip_unseen(ehci, async);
trace_usb_ehci_doorbell_ack();
ehci->usbcmd &= ~USBCMD_IAAD;
ehci_raise_irq(ehci, USBSTS_IAA);
@ -2385,7 +2397,7 @@ static void ehci_advance_periodic_state(EHCIState *ehci)
ehci_set_fetch_addr(ehci, async,entry);
ehci_set_state(ehci, async, EST_FETCHENTRY);
ehci_advance_state(ehci, async);
ehci_queues_rip_unused(ehci, async, 0);
ehci_queues_rip_unused(ehci, async);
break;
default: