USB: EHCI: use hrtimer for unlinking empty async QHs

This patch (as1583) changes ehci-hcd to use an hrtimer event for
unlinking empty (unused) async QHs instead of using a kernel timer.

The check for empty QHs is moved to a new routine, where it doesn't
require going through an entire scan of both the async and periodic
schedules.  And it can unlink multiple QHs at once, unlike the current
code.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
index 8ca5f152f5bd..a823290b5139 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 */
+        6 * NSEC_PER_MSEC,      /* EHCI_HRTIMER_ASYNC_UNLINKS */
         10 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_IAA_WATCHDOG */
         10 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_DISABLE_PERIODIC */
         15 * NSEC_PER_MSEC,     /* EHCI_HRTIMER_DISABLE_ASYNC */
@@ -347,6 +348,7 @@ 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 */
+        unlink_empty_async,             /* EHCI_HRTIMER_ASYNC_UNLINKS */
         ehci_iaa_watchdog,              /* EHCI_HRTIMER_IAA_WATCHDOG */
         ehci_disable_PSE,               /* EHCI_HRTIMER_DISABLE_PERIODIC */
         ehci_disable_ASE,               /* EHCI_HRTIMER_DISABLE_ASYNC */