USB: EHCI: add need_io_watchdog flag to ehci_hcd

Basically the io watchdog is only useful for those quirk HCDs. For most
good ones, it only brings unnecessary wakeups.  At least, I know the
Intel EHCI HCDs should turn off the flag.

Signed-off-by: Alek Du <alek.du@intel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 54715b875759..2dc15f3ad143 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -127,6 +127,8 @@ timer_action(struct ehci_hcd *ehci, enum ehci_timer_action action)
 
                 switch (action) {
                 case TIMER_IO_WATCHDOG:
+                        if (!ehci->need_io_watchdog)
+                                return;
                         t = EHCI_IO_JIFFIES;
                         break;
                 case TIMER_ASYNC_OFF:
@@ -508,6 +510,10 @@ static int ehci_init(struct usb_hcd *hcd)
 
         spin_lock_init(&ehci->lock);
 
+        /*
+         * keep io watchdog by default, those good HCDs could turn off it later
+         */
+        ehci->need_io_watchdog = 1;
         init_timer(&ehci->watchdog);
         ehci->watchdog.function = ehci_watchdog;
         ehci->watchdog.data = (unsigned long) ehci;