1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
index 0e28bae78d18..eb896a2c8f2e 100644
--- a/drivers/usb/host/ehci-timer.c
+++ b/drivers/usb/host/ehci-timer.c
@@ -76,6 +76,7 @@ static unsigned event_delays_ns[] = {
         10 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_IAA_WATCHDOG */
         10 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_DISABLE_PERIODIC */
         15 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_DISABLE_ASYNC */
+        100 * NSEC_PER_MSEC,    /* EHCI_HRTIMER_IO_WATCHDOG */
 };
 
 /* Enable a pending hrtimer event */
@@ -332,6 +333,25 @@ static void ehci_iaa_watchdog(struct ehci_hcd *ehci)
 }
 
 
+/* Enable the I/O watchdog, if appropriate */
+static void turn_on_io_watchdog(struct ehci_hcd *ehci)
+{
+        /* Not needed if the controller isn't running or it's already enabled */
+        if (ehci->rh_state != EHCI_RH_RUNNING ||
+                        (ehci->enabled_hrtimer_events &
+                                BIT(EHCI_HRTIMER_IO_WATCHDOG)))
+                return;
+
+        /*
+         * Isochronous transfers always need the watchdog.
+         * For other sorts we use it only if the flag is set.
+         */
+        if (ehci->isoc_count > 0 || (ehci->need_io_watchdog &&
+                        ehci->async_count + ehci->intr_count > 0))
+                ehci_enable_event(ehci, EHCI_HRTIMER_IO_WATCHDOG, true);
+}
+
+
 /*
  * Handler functions for the hrtimer event types.
  * Keep this array in the same order as the event types indexed by
@@ -347,6 +367,7 @@ static void (*event_handlers[])(struct ehci_hcd *) = {
         ehci_iaa_watchdog,              /* EHCI_HRTIMER_IAA_WATCHDOG */
         ehci_disable_PSE,               /* EHCI_HRTIMER_DISABLE_PERIODIC */
         ehci_disable_ASE,               /* EHCI_HRTIMER_DISABLE_ASYNC */
+        ehci_work,                      /* EHCI_HRTIMER_IO_WATCHDOG */
 };
 
 static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)