On Fri, 18 Jan 2013, Alan Stern wrote:
> Well, I guess there's no choice but to go back to the one-at-a-time
> approach. I'll write a proper patch for that.
And here it is at last. This completely replaces the earlier patch.
Alan Stern
Index: 3.7/drivers/usb/host/ehci-timer.c
===================================================================
--- 3.7.orig/drivers/usb/host/ehci-timer.c
+++ 3.7/drivers/usb/host/ehci-timer.c
@@ -113,21 +113,22 @@ static void ehci_poll_ASS(struct ehci_hc
if (want != actual) {
- /* Poll again later, but give up after about 20 ms */
- if (ehci->ASS_poll_count++ < 20) {
- ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
- return;
- }
- ehci_dbg(ehci, "Waited too long for the async schedule status
(%x/%x), giving up\n",
- want, actual);
+ /* Poll again later */
+ ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
+ ++ehci->ASS_poll_count;
+ return;
}
+
+ if (ehci->ASS_poll_count > 20)
+ ehci_dbg(ehci, "ASS poll count reached %d\n",
+ ehci->ASS_poll_count);
ehci->ASS_poll_count = 0;
/* The status is up-to-date; restart or stop the schedule as needed */
if (want == 0) { /* Stopped */
- if (ehci->async_count > 0)
+ if (ehci->async_count > 0) {
ehci_set_command_bit(ehci, CMD_ASE);
-
+ }
} else { /* Running */
if (ehci->async_count == 0) {
@@ -159,14 +160,14 @@ static void ehci_poll_PSS(struct ehci_hc
if (want != actual) {
- /* Poll again later, but give up after about 20 ms */
- if (ehci->PSS_poll_count++ < 20) {
- ehci_enable_event(ehci, EHCI_HRTIMER_POLL_PSS, true);
- return;
- }
- ehci_dbg(ehci, "Waited too long for the periodic schedule
status (%x/%x), giving up\n",
- want, actual);
+ /* Poll again later */
+ ehci_enable_event(ehci, EHCI_HRTIMER_POLL_PSS, true);
+ return;
}
+
+ if (ehci->PSS_poll_count > 20)
+ ehci_dbg(ehci, "PSS poll count reached %d\n",
+ ehci->PSS_poll_count);
ehci->PSS_poll_count = 0;
/* The status is up-to-date; restart or stop the schedule as needed */
Index: 3.7/drivers/usb/host/ehci-q.c
===================================================================
--- 3.7.orig/drivers/usb/host/ehci-q.c
+++ 3.7/drivers/usb/host/ehci-q.c
@@ -1203,17 +1203,26 @@ static void start_iaa_cycle(struct ehci_
if (ehci->async_iaa || ehci->async_unlinking)
return;
- /* Do all the waiting QHs at once */
- ehci->async_iaa = ehci->async_unlink;
- ehci->async_unlink = NULL;
-
/* If the controller isn't running, we don't have to wait for it */
if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) {
+
+ /* Do all the waiting QHs */
+ ehci->async_iaa = ehci->async_unlink;
+ ehci->async_unlink = NULL;
+
if (!nested) /* Avoid recursion */
end_unlink_async(ehci);
/* Otherwise start a new IAA cycle */
} else if (likely(ehci->rh_state == EHCI_RH_RUNNING)) {
+ struct ehci_qh *qh;
+
+ /* Do only the first waiting QH (nVidia bug?) */
+ qh = ehci->async_unlink;
+ ehci->async_iaa = qh;
+ ehci->async_unlink = qh->unlink_next;
+ qh->unlink_next = NULL;
+
/* Make sure the unlinks are all visible to the hardware */
wmb();
@@ -1261,34 +1270,35 @@ static void end_unlink_async(struct ehci
}
}
+static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
+
static void unlink_empty_async(struct ehci_hcd *ehci)
{
- struct ehci_qh *qh, *next;
- bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+ struct ehci_qh *qh;
+ struct ehci_qh *qh_to_unlink = NULL;
bool check_unlinks_later = false;
+ int count = 0;
- /* Unlink all the async QHs that have been empty for a timer cycle */
- next = ehci->async->qh_next.qh;
- while (next) {
- qh = next;
- next = qh->qh_next.qh;
-
+ /* Find the last async QH which has been empty for a timer cycle */
+ for (qh = ehci->async->qh_next.qh; qh; qh = qh->qh_next.qh) {
if (list_empty(&qh->qtd_list) &&
qh->qh_state == QH_STATE_LINKED) {
- if (!stopped && qh->unlink_cycle ==
- ehci->async_unlink_cycle)
+ ++count;
+ if (qh->unlink_cycle == ehci->async_unlink_cycle)
check_unlinks_later = true;
else
- single_unlink_async(ehci, qh);
+ qh_to_unlink = qh;
}
}
- /* Start a new IAA cycle if any QHs are waiting for it */
- if (ehci->async_unlink)
- start_iaa_cycle(ehci, false);
+ /* If nothing else is being unlinked, unlink the last empty QH */
+ if (!ehci->async_iaa && !ehci->async_unlink && qh_to_unlink) {
+ start_unlink_async(ehci, qh_to_unlink);
+ --count;
+ }
- /* QHs that haven't been empty for long enough will be handled later */
- if (check_unlinks_later) {
+ /* Other QHs will be handled later */
+ if (count > 0) {
ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
++ehci->async_unlink_cycle;
}
--
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