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path: root/drivers/usb/host/ehci-sched.c
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Diffstat (limited to 'drivers/usb/host/ehci-sched.c')
-rw-r--r--drivers/usb/host/ehci-sched.c47
1 files changed, 45 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 8e3c878f38cf..66310894ad97 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -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 +649,27 @@ 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)
+{
+ 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;
@@ -889,6 +927,9 @@ 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 */
@@ -924,9 +965,11 @@ static void scan_intr(struct ehci_hcd *ehci)
* in qh_unlink_periodic().
*/
temp = qh_completions(ehci, qh);
- if (unlikely(temp || (list_empty(&qh->qtd_list) &&
- qh->qh_state == QH_STATE_LINKED)))
+ if (unlikely(temp))
start_unlink_intr(ehci, qh);
+ else if (unlikely(list_empty(&qh->qtd_list) &&
+ qh->qh_state == QH_STATE_LINKED))
+ start_unlink_intr_wait(ehci, qh);
}
}
}