3 files changed, 12 insertions, 4 deletions

diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 6147770b4347..7a0a3e8d5d72 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -708,7 +708,7 @@ static void setup_APIC_timer(unsigned int clocks)
         local_irq_save(flags);
 
         /* wait for irq slice */
-        if (vxtime.hpet_address) {
+        if (vxtime.hpet_address && hpet_use_timer) {
                 int trigger = hpet_readl(HPET_T0_CMP);
                 while (hpet_readl(HPET_COUNTER) >= trigger)
                         /* do nothing */ ;
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index dba7237be5c1..3c58c30506a1 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -59,7 +59,7 @@ static int notsc __initdata = 0;
 unsigned int cpu_khz;                                   /* TSC clocks / usec, not used here */
 static unsigned long hpet_period;                       /* fsecs / HPET clock */
 unsigned long hpet_tick;                                /* HPET clocks / interrupt */
-static int hpet_use_timer;                              /* Use counter of hpet for time keeping, otherwise PIT */
+int hpet_use_timer;                             /* Use counter of hpet for time keeping, otherwise PIT */
 unsigned long vxtime_hz = PIT_TICK_RATE;
 int report_lost_ticks;                          /* command line option */
 unsigned long long monotonic_base;
@@ -326,7 +326,10 @@ static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
             print_symbol("rip %s\n", regs->rip);
             if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
                     printk(KERN_WARNING "Falling back to HPET\n");
-                    vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
+                    if (hpet_use_timer)
+                        vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
+                    else
+                        vxtime.last = hpet_readl(HPET_COUNTER);
                     vxtime.mode = VXTIME_HPET;
                     do_gettimeoffset = do_gettimeoffset_hpet;
             }
@@ -988,7 +991,10 @@ void __init time_init_gtod(void)
                 notsc = 1;
         if (vxtime.hpet_address && notsc) {
                 timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
-                vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
+                if (hpet_use_timer)
+                        vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
+                else
+                        vxtime.last = hpet_readl(HPET_COUNTER);
                 vxtime.mode = VXTIME_HPET;
                 do_gettimeoffset = do_gettimeoffset_hpet;
 #ifdef CONFIG_X86_PM_TIMER
diff --git a/include/asm-x86_64/hpet.h b/include/asm-x86_64/hpet.h
index c20c28f5c7a0..08b75c15269a 100644
--- a/include/asm-x86_64/hpet.h
+++ b/include/asm-x86_64/hpet.h
@@ -55,6 +55,8 @@ extern int is_hpet_enabled(void);
 extern int hpet_rtc_timer_init(void);
 extern int oem_force_hpet_timer(void);
 
+extern int hpet_use_timer;
+
 #ifdef CONFIG_HPET_EMULATE_RTC
 extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
 extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);