[PATCH] x86_64: [PATCH] timer resume

At resume time, TSC's value or something similar might be changed a lot
against suspend time. This could make system gets a very big lost ticks.
See http://bugzilla.kernel.org/show_bug.cgi?id=5825

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 17 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/pmtimer.c b/arch/x86_64/kernel/pmtimer.c
index feb5f108dd26..8b2655ae4e61 100644
--- a/arch/x86_64/kernel/pmtimer.c
+++ b/arch/x86_64/kernel/pmtimer.c
@@ -80,6 +80,11 @@ int pmtimer_mark_offset(void)
         return lost - 1;
 }
 
+void pmtimer_resume(void)
+{
+        last_pmtmr_tick = inl(pmtmr_ioport);
+}
+
 unsigned int do_gettimeoffset_pm(void)
 {
         u32 now, offset, delta = 0;
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 91a448a86ebd..c1f76055b578 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -1047,9 +1047,21 @@ static int timer_resume(struct sys_device *dev)
         write_seqlock_irqsave(&xtime_lock,flags);
         xtime.tv_sec = sec;
         xtime.tv_nsec = 0;
+        if (vxtime.mode == VXTIME_HPET) {
+                if (hpet_use_timer)
+                        vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
+                else
+                        vxtime.last = hpet_readl(HPET_COUNTER);
+#ifdef CONFIG_X86_PM_TIMER
+        } else if (vxtime.mode == VXTIME_PMTMR) {
+                pmtimer_resume();
+#endif
+        } else
+                vxtime.last_tsc = get_cycles_sync();
         write_sequnlock_irqrestore(&xtime_lock,flags);
         jiffies += sleep_length;
         wall_jiffies += sleep_length;
+        monotonic_base += sleep_length * (NSEC_PER_SEC/HZ);
         touch_softlockup_watchdog();
         return 0;
 }