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>
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 1a78277..303c36c 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -84,6 +84,7 @@
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_ASYNC_UNLINKS, /* Unlink empty async QHs */
EHCI_HRTIMER_IAA_WATCHDOG, /* Handle lost IAA interrupts */
EHCI_HRTIMER_DISABLE_PERIODIC, /* Wait to disable periodic sched */
EHCI_HRTIMER_DISABLE_ASYNC, /* Wait to disable async sched */
@@ -123,6 +124,7 @@
struct ehci_qh *async_unlink_last;
struct ehci_qh *async_iaa;
struct ehci_qh *qh_scan_next;
+ unsigned async_unlink_cycle;
unsigned async_count; /* async activity count */
/* periodic schedule support */
@@ -232,7 +234,6 @@
enum ehci_timer_action {
TIMER_IO_WATCHDOG,
- TIMER_ASYNC_SHRINK,
};
static inline void
@@ -382,7 +383,6 @@
struct ehci_qtd *dummy;
struct ehci_qh *unlink_next; /* next on unlink list */
- unsigned long unlink_time;
unsigned unlink_cycle;
unsigned stamp;