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-rw-r--r--drivers/usb/host/ehci-hcd.c3
-rw-r--r--drivers/usb/host/ehci-q.c56
-rw-r--r--drivers/usb/host/ehci-timer.c2
-rw-r--r--drivers/usb/host/ehci.h3
4 files changed, 59 insertions, 5 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 84c41262109c..a93d445b63a4 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -566,6 +566,9 @@ static int ehci_init(struct usb_hcd *hcd)
/* Accept arbitrarily long scatter-gather lists */
if (!(hcd->driver->flags & HCD_LOCAL_MEM))
hcd->self.sg_tablesize = ~0;
+
+ /* Prepare for unlinking active QHs */
+ ehci->old_current = ~0;
return 0;
}
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 15dcae8f0631..a24341ef863d 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -1341,14 +1341,60 @@ static void end_unlink_async(struct ehci_hcd *ehci)
* after the IAA interrupt occurs. In self-defense, always go
* through two IAA cycles for each QH.
*/
- else if (qh->qh_state == QH_STATE_UNLINK_WAIT) {
+ else if (qh->qh_state == QH_STATE_UNLINK) {
+ /*
+ * Second IAA cycle has finished. Process only the first
+ * waiting QH (NVIDIA (?) bug).
+ */
+ list_move_tail(&qh->unlink_node, &ehci->async_idle);
+ }
+
+ /*
+ * AMD/ATI (?) bug: The HC can continue to use an active QH long
+ * after the IAA interrupt occurs. To prevent problems, QHs that
+ * may still be active will wait until 2 ms have passed with no
+ * change to the hw_current and hw_token fields (this delay occurs
+ * between the two IAA cycles).
+ *
+ * The EHCI spec (4.8.2) says that active QHs must not be removed
+ * from the async schedule and recommends waiting until the QH
+ * goes inactive. This is ridiculous because the QH will _never_
+ * become inactive if the endpoint NAKs indefinitely.
+ */
+
+ /* Some reasons for unlinking guarantee the QH can't be active */
+ else if (qh->unlink_reason & (QH_UNLINK_HALTED |
+ QH_UNLINK_SHORT_READ | QH_UNLINK_DUMMY_OVERLAY))
+ goto DelayDone;
+
+ /* The QH can't be active if the queue was and still is empty... */
+ else if ((qh->unlink_reason & QH_UNLINK_QUEUE_EMPTY) &&
+ list_empty(&qh->qtd_list))
+ goto DelayDone;
+
+ /* ... or if the QH has halted */
+ else if (qh->hw->hw_token & cpu_to_hc32(ehci, QTD_STS_HALT))
+ goto DelayDone;
+
+ /* Otherwise we have to wait until the QH stops changing */
+ else {
+ __hc32 qh_current, qh_token;
+
+ qh_current = qh->hw->hw_current;
+ qh_token = qh->hw->hw_token;
+ if (qh_current != ehci->old_current ||
+ qh_token != ehci->old_token) {
+ ehci->old_current = qh_current;
+ ehci->old_token = qh_token;
+ ehci_enable_event(ehci,
+ EHCI_HRTIMER_ACTIVE_UNLINK, true);
+ return;
+ }
+ DelayDone:
qh->qh_state = QH_STATE_UNLINK;
early_exit = true;
}
-
- /* Otherwise process only the first waiting QH (NVIDIA bug?) */
- else
- list_move_tail(&qh->unlink_node, &ehci->async_idle);
+ ehci->old_current = ~0; /* Prepare for next QH */
/* Start a new IAA cycle if any QHs are waiting for it */
if (!list_empty(&ehci->async_unlink))
diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
index 6bea4d553ec5..69f50e6533a6 100644
--- a/drivers/usb/host/ehci-timer.c
+++ b/drivers/usb/host/ehci-timer.c
@@ -72,6 +72,7 @@ static unsigned event_delays_ns[] = {
1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_DEAD */
1125 * NSEC_PER_USEC, /* EHCI_HRTIMER_UNLINK_INTR */
2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_FREE_ITDS */
+ 2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ACTIVE_UNLINK */
5 * NSEC_PER_MSEC, /* EHCI_HRTIMER_START_UNLINK_INTR */
6 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ASYNC_UNLINKS */
10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IAA_WATCHDOG */
@@ -395,6 +396,7 @@ static void (*event_handlers[])(struct ehci_hcd *) = {
ehci_handle_controller_death, /* EHCI_HRTIMER_POLL_DEAD */
ehci_handle_intr_unlinks, /* EHCI_HRTIMER_UNLINK_INTR */
end_free_itds, /* EHCI_HRTIMER_FREE_ITDS */
+ end_unlink_async, /* EHCI_HRTIMER_ACTIVE_UNLINK */
ehci_handle_start_intr_unlinks, /* EHCI_HRTIMER_START_UNLINK_INTR */
unlink_empty_async, /* EHCI_HRTIMER_ASYNC_UNLINKS */
ehci_iaa_watchdog, /* EHCI_HRTIMER_IAA_WATCHDOG */
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index f11b9dc53981..b13894550139 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -110,6 +110,7 @@ enum ehci_hrtimer_event {
EHCI_HRTIMER_POLL_DEAD, /* Wait for dead controller to stop */
EHCI_HRTIMER_UNLINK_INTR, /* Wait for interrupt QH unlink */
EHCI_HRTIMER_FREE_ITDS, /* Wait for unused iTDs and siTDs */
+ EHCI_HRTIMER_ACTIVE_UNLINK, /* Wait while unlinking an active QH */
EHCI_HRTIMER_START_UNLINK_INTR, /* Unlink empty interrupt QHs */
EHCI_HRTIMER_ASYNC_UNLINKS, /* Unlink empty async QHs */
EHCI_HRTIMER_IAA_WATCHDOG, /* Handle lost IAA interrupts */
@@ -156,6 +157,8 @@ struct ehci_hcd { /* one per controller */
struct list_head async_idle;
unsigned async_unlink_cycle;
unsigned async_count; /* async activity count */
+ __hc32 old_current; /* Test for QH becoming */
+ __hc32 old_token; /* inactive during unlink */
/* periodic schedule support */
#define DEFAULT_I_TDPS 1024 /* some HCs can do less */