@@ -484,6 +484,7 @@ static int ehci_init(struct usb_hcd *hcd)
ehci->periodic_size = DEFAULT_I_TDPS;
INIT_LIST_HEAD(&ehci->async_unlink);
INIT_LIST_HEAD(&ehci->async_idle);
+ INIT_LIST_HEAD(&ehci->intr_unlink_wait);
INIT_LIST_HEAD(&ehci->intr_unlink);
INIT_LIST_HEAD(&ehci->intr_qh_list);
INIT_LIST_HEAD(&ehci->cached_itd_list);
@@ -345,6 +345,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
end_unlink_async(ehci);
unlink_empty_async_suspended(ehci);
+ ehci_handle_start_intr_unlinks(ehci);
ehci_handle_intr_unlinks(ehci);
end_free_itds(ehci);
@@ -93,6 +93,7 @@ static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
qh->qh_dma = dma;
// INIT_LIST_HEAD (&qh->qh_list);
INIT_LIST_HEAD (&qh->qtd_list);
+ INIT_LIST_HEAD(&qh->unlink_node);
/* dummy td enables safe urb queuing */
qh->dummy = ehci_qtd_alloc (ehci, flags);
@@ -601,12 +601,29 @@ static void qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
list_del(&qh->intr_node);
}
+static void cancel_unlink_wait_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
+{
+ if (qh->qh_state != QH_STATE_LINKED ||
+ list_empty(&qh->unlink_node))
+ return;
+
+ list_del_init(&qh->unlink_node);
+
+ /*
+ * TODO: disable the event of EHCI_HRTIMER_START_UNLINK_INTR for
+ * avoiding unnecessary CPU wakeup
+ */
+}
+
static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
/* If the QH isn't linked then there's nothing we can do. */
if (qh->qh_state != QH_STATE_LINKED)
return;
+ /* if the qh is waiting for unlink, cancel it now */
+ cancel_unlink_wait_intr(ehci, qh);
+
qh_unlink_periodic (ehci, qh);
/* Make sure the unlinks are visible before starting the timer */
@@ -632,6 +649,31 @@ static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
}
}
+/*
+ * It is common only one intr URB is scheduled on one qh, and
+ * given complete() is run in tasklet context, introduce a bit
+ * delay to avoid unlink qh too early.
+ */
+static void start_unlink_intr_wait(struct ehci_hcd *ehci,
+ struct ehci_qh *qh)
+{
+ /* If the QH isn't linked then there's nothing we can do. */
+ if (qh->qh_state != QH_STATE_LINKED)
+ return;
+
+ qh->unlink_cycle = ehci->intr_unlink_wait_cycle;
+
+ /* New entries go at the end of the intr_unlink_wait list */
+ list_add_tail(&qh->unlink_node, &ehci->intr_unlink_wait);
+
+ if (ehci->rh_state < EHCI_RH_RUNNING)
+ ehci_handle_start_intr_unlinks(ehci);
+ else if (ehci->intr_unlink_wait.next == &qh->unlink_node) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
+ ++ehci->intr_unlink_wait_cycle;
+ }
+}
+
static void end_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
struct ehci_qh_hw *hw = qh->hw;
@@ -884,6 +926,9 @@ static int intr_submit (
if (qh->qh_state == QH_STATE_IDLE) {
qh_refresh(ehci, qh);
qh_link_periodic(ehci, qh);
+ } else {
+ /* cancel unlink wait for the qh */
+ cancel_unlink_wait_intr(ehci, qh);
}
/* ... update usbfs periodic stats */
@@ -921,7 +966,7 @@ static void scan_intr(struct ehci_hcd *ehci)
temp = qh_completions(ehci, qh);
if (unlikely(temp || (list_empty(&qh->qtd_list) &&
qh->qh_state == QH_STATE_LINKED)))
- start_unlink_intr(ehci, qh);
+ start_unlink_intr_wait(ehci, qh);
}
}
}
@@ -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 */
+ 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 */
10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_PERIODIC */
@@ -98,7 +99,6 @@ static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
}
}
-
/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
static void ehci_poll_ASS(struct ehci_hcd *ehci)
{
@@ -215,6 +215,36 @@ static void ehci_handle_controller_death(struct ehci_hcd *ehci)
/* Not in process context, so don't try to reset the controller */
}
+/* start to unlink interrupt QHs */
+static void ehci_handle_start_intr_unlinks(struct ehci_hcd *ehci)
+{
+ bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+
+ /*
+ * Process all the QHs on the intr_unlink list that were added
+ * before the current unlink cycle began. The list is in
+ * temporal order, so stop when we reach the first entry in the
+ * current cycle. But if the root hub isn't running then
+ * process all the QHs on the list.
+ */
+ while (!list_empty(&ehci->intr_unlink_wait)) {
+ struct ehci_qh *qh;
+
+ qh = list_first_entry(&ehci->intr_unlink_wait,
+ struct ehci_qh, unlink_node);
+ if (!stopped && (qh->unlink_cycle ==
+ ehci->intr_unlink_wait_cycle))
+ break;
+ list_del_init(&qh->unlink_node);
+ start_unlink_intr(ehci, qh);
+ }
+
+ /* Handle remaining entries later */
+ if (!list_empty(&ehci->intr_unlink_wait)) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
+ ++ehci->intr_unlink_wait_cycle;
+ }
+}
/* Handle unlinked interrupt QHs once they are gone from the hardware */
static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci)
@@ -236,7 +266,7 @@ static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci)
unlink_node);
if (!stopped && qh->unlink_cycle == ehci->intr_unlink_cycle)
break;
- list_del(&qh->unlink_node);
+ list_del_init(&qh->unlink_node);
end_unlink_intr(ehci, qh);
}
@@ -363,6 +393,7 @@ 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 */
+ ehci_handle_start_intr_unlinks, /* EHCI_HRTIMER_START_UNLINK_INTR */
unlink_empty_async, /* EHCI_HRTIMER_ASYNC_UNLINKS */
ehci_iaa_watchdog, /* EHCI_HRTIMER_IAA_WATCHDOG */
ehci_disable_PSE, /* EHCI_HRTIMER_DISABLE_PERIODIC */
@@ -88,6 +88,7 @@ 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_START_UNLINK_INTR, /* Unlink empty interrupt QHs */
EHCI_HRTIMER_ASYNC_UNLINKS, /* Unlink empty async QHs */
EHCI_HRTIMER_IAA_WATCHDOG, /* Handle lost IAA interrupts */
EHCI_HRTIMER_DISABLE_PERIODIC, /* Wait to disable periodic sched */
@@ -143,7 +144,9 @@ struct ehci_hcd { /* one per controller */
unsigned i_thresh; /* uframes HC might cache */
union ehci_shadow *pshadow; /* mirror hw periodic table */
+ struct list_head intr_unlink_wait;
struct list_head intr_unlink;
+ unsigned intr_unlink_wait_cycle;
unsigned intr_unlink_cycle;
unsigned now_frame; /* frame from HC hardware */
unsigned last_iso_frame; /* last frame scanned for iso */