Commit 056761e5 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman

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: default avatarDavid Brownell <>
Cc: Alan Stern <>
Cc: Leonid <>
Cc: stable <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 4b828abe
......@@ -177,6 +177,15 @@ timer_action_done (struct ehci_hcd *ehci, enum ehci_timer_action action)
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)
& ehci->actions))
if (!test_and_set_bit (action, &ehci->actions)) {
unsigned long t;
......@@ -192,15 +201,7 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
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))
mod_timer (&ehci->watchdog, t);
mod_timer(&ehci->watchdog, t + jiffies);
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