USB: ehci - fix timer regression
This patch fixes a regression in the EHCI driver's TIMER_IO_WATCHDOG
behavior. The patch "USB: EHCI: add separate IAA watchdog timer" changed
how that timer is handled, so that short timeouts on the remaining
timer (unfortunately, overloaded) would never be used.
This takes a more direct approach, reorganizing the code slightly to
be explicit about only the I/O watchdog role now being overridable.
It also replaces a now-obsolete comment describing older timer behavior.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Leonid <leonidv11@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 35a0309..90245fd 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -177,6 +177,15 @@
static inline void
timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
{
+ /* Don't override timeouts which shrink or (later) disable
+ * the async ring; just the I/O watchdog. Note that if a
+ * SHRINK were pending, OFF would never be requested.
+ */
+ if (timer_pending(&ehci->watchdog)
+ && ((BIT(TIMER_ASYNC_SHRINK) | BIT(TIMER_ASYNC_OFF))
+ & ehci->actions))
+ return;
+
if (!test_and_set_bit (action, &ehci->actions)) {
unsigned long t;
@@ -192,15 +201,7 @@
t = EHCI_SHRINK_JIFFIES;
break;
}
- t += jiffies;
- // all timings except IAA watchdog can be overridden.
- // async queue SHRINK often precedes IAA. while it's ready
- // to go OFF neither can matter, and afterwards the IO
- // watchdog stops unless there's still periodic traffic.
- if (time_before_eq(t, ehci->watchdog.expires)
- && timer_pending (&ehci->watchdog))
- return;
- mod_timer (&ehci->watchdog, t);
+ mod_timer(&ehci->watchdog, t + jiffies);
}
}