The patch titled
clocksource: fix resume logic
has been added to the -mm tree. Its filename is
clocksource-fix-resume-logic.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: clocksource: fix resume logic
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
We need to make sure that the clocksources are resumed, when timekeeping is
resumed. The current resume logic does not guarantee this.
Add a resume function pointer to the clocksource struct, so clocksource
drivers which need to reinitialize the clocksource can provide a resume
function.
Add a resume function, which calls the maybe available clocksource resume
functions and resets the watchdog function, so a stable TSC can be used
accross suspend/resume.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: john stultz <johnstul@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/clocksource.h | 3 ++
kernel/time/clocksource.c | 45 ++++++++++++++++++++++++++++++++++
kernel/timer.c | 2 +
3 files changed, 50 insertions(+)
diff -puN include/linux/clocksource.h~clocksource-fix-resume-logic include/linux/clocksource.h
--- a/include/linux/clocksource.h~clocksource-fix-resume-logic
+++ a/include/linux/clocksource.h
@@ -49,6 +49,7 @@ struct clocksource;
* @shift: cycle to nanosecond divisor (power of two)
* @flags: flags describing special properties
* @vread: vsyscall based read
+ * @resume: resume function for the clocksource, if necessary
* @cycle_interval: Used internally by timekeeping core, please ignore.
* @xtime_interval: Used internally by timekeeping core, please ignore.
*/
@@ -65,6 +66,7 @@ struct clocksource {
u32 shift;
unsigned long flags;
cycle_t (*vread)(void);
+ void (*resume)(void);
/* timekeeping specific data, ignore */
cycle_t cycle_interval;
@@ -209,6 +211,7 @@ static inline void clocksource_calculate
extern int clocksource_register(struct clocksource*);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
+extern void clocksource_resume(void);
#ifdef CONFIG_GENERIC_TIME_VSYSCALL
extern void update_vsyscall(struct timespec *ts, struct clocksource *c);
diff -puN kernel/time/clocksource.c~clocksource-fix-resume-logic kernel/time/clocksource.c
--- a/kernel/time/clocksource.c~clocksource-fix-resume-logic
+++ a/kernel/time/clocksource.c
@@ -74,6 +74,8 @@ static struct clocksource *watchdog;
static struct timer_list watchdog_timer;
static DEFINE_SPINLOCK(watchdog_lock);
static cycle_t watchdog_last;
+static int watchdog_resumed;
+
/*
* Interval: 0.5sec Treshold: 0.0625s
*/
@@ -98,15 +100,26 @@ static void clocksource_watchdog(unsigne
struct clocksource *cs, *tmp;
cycle_t csnow, wdnow;
int64_t wd_nsec, cs_nsec;
+ int resumed;
spin_lock(&watchdog_lock);
+ resumed = watchdog_resumed;
+ if (unlikely(resumed))
+ watchdog_resumed = 0;
+
wdnow = watchdog->read();
wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
watchdog_last = wdnow;
list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
csnow = cs->read();
+
+ if (unlikely(resumed)) {
+ cs->wd_last = csnow;
+ continue;
+ }
+
/* Initialized ? */
if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
@@ -136,6 +149,13 @@ static void clocksource_watchdog(unsigne
}
spin_unlock(&watchdog_lock);
}
+static void clocksource_resume_watchdog(void)
+{
+ spin_lock(&watchdog_lock);
+ watchdog_resumed = 1;
+ spin_unlock(&watchdog_lock);
+}
+
static void clocksource_check_watchdog(struct clocksource *cs)
{
struct clocksource *cse;
@@ -182,9 +202,34 @@ static void clocksource_check_watchdog(s
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
}
+
+static inline void clocksource_resume_watchdog(void) { }
#endif
/**
+ * clocksource_resume - resume the clocksource(s)
+ */
+void clocksource_resume(void)
+{
+ struct list_head *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&clocksource_lock, flags);
+
+ list_for_each(tmp, &clocksource_list) {
+ struct clocksource *cs;
+
+ cs = list_entry(tmp, struct clocksource, list);
+ if (cs->resume)
+ cs->resume();
+ }
+
+ clocksource_resume_watchdog();
+
+ spin_unlock_irqrestore(&clocksource_lock, flags);
+}
+
+/**
* clocksource_get_next - Returns the selected clocksource
*
*/
diff -puN kernel/timer.c~clocksource-fix-resume-logic kernel/timer.c
--- a/kernel/timer.c~clocksource-fix-resume-logic
+++ a/kernel/timer.c
@@ -1499,6 +1499,8 @@ unregister_time_interpolator(struct time
prev = &curr->next;
}
+ clocksource_resume();
+
write_seqlock_irqsave(&xtime_lock, flags);
if (ti == time_interpolator) {
/* we lost the best time-interpolator: */
_
Patches currently in -mm which might be from tglx@xxxxxxxxxxxxx are
origin.patch
git-arm.patch
git-avr32.patch
git-ieee1394.patch
git-input.patch
h8300-generic-irq.patch
optimize-timespec_trunc.patch
kernel-irq-procc-unprotected-iteration-over-the-irq-action-list-in-name_unique.patch
add-support-for-deferrable-timers-respun.patch
irq-check-for-percpu-flag-only-when-adding-first-irqaction.patch
move-timekeeping-code-to-timekeepingc.patch
ignore-stolen-time-in-the-softlockup-watchdog.patch
replace-deprecated-sa_xxx-interrupt-flags.patch
deprecate-sa_xxx-interrupt-flags-v2.patch
pad-irq_desc-to-internode-cacheline-size.patch
highres-dyntick-prevent-xtime-lock-contention.patch
introduce-a-handy-list_first_entry-macro-v2.patch
the-scheduled-einval-for-invalid-timevals-in-setitimer.patch
sched-fix-idle-load-balancing-in-softirqd-context.patch
sched-dynticks-idle-load-balancing-v3.patch
declare-struct-ktime.patch
add-irqf_irqpoll-flag-common-code.patch
add-irqf_irqpoll-flag-on-x86_64.patch
add-irqf_irqpoll-flag-on-i386.patch
add-irqf_irqpoll-flag-on-ia64.patch
add-irqf_irqpoll-flag-on-sh.patch
add-irqf_irqpoll-flag-on-arm.patch
clocksource-fix-resume-logic.patch
acpi-keep-tsc-stable-when-lapic_timer_c2_ok-is-set.patch
clockevents-fix-resume-logic.patch
timer_stats-slimmed-down-using-statistics-infrastucture.patch
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