x86: fix freeze in x86_64 RTC update code in time_64.c

[safe/jmp/linux-2.6] / arch / x86 / kernel / time_64.c

diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
index aca081c..4ad1f7a 100644 (file)
--- a/arch/x86/kernel/time_64.c
+++ b/arch/x86/kernel/time_64.c
@@ -1,6 +1,4 @@
 /*
- *  linux/arch/x86-64/kernel/time.c
- *
  *  "High Precision Event Timer" based timekeeping.
  *
  *  Copyright (c) 1991,1992,1995  Linus Torvalds
@@ -84,18 +82,15 @@ static int set_rtc_mmss(unsigned long nowtime)
        int retval = 0;
        int real_seconds, real_minutes, cmos_minutes;
        unsigned char control, freq_select;
+       unsigned long flags;
 
 /*
- * IRQs are disabled when we're called from the timer interrupt,
- * no need for spin_lock_irqsave()
+ * set_rtc_mmss is called when irqs are enabled, so disable irqs here
  */
-
-       spin_lock(&rtc_lock);
-
+       spin_lock_irqsave(&rtc_lock, flags);
 /*
  * Tell the clock it's being set and stop it.
  */
-
        control = CMOS_READ(RTC_CONTROL);
        CMOS_WRITE(control | RTC_SET, RTC_CONTROL);
 
@@ -140,7 +135,7 @@ static int set_rtc_mmss(unsigned long nowtime)
        CMOS_WRITE(control, RTC_CONTROL);
        CMOS_WRITE(freq_select, RTC_FREQ_SELECT);
 
-       spin_unlock(&rtc_lock);
+       spin_unlock_irqrestore(&rtc_lock, flags);
 
        return retval;
 }
@@ -150,48 +145,6 @@ int update_persistent_clock(struct timespec now)
        return set_rtc_mmss(now.tv_sec);
 }
 
-void main_timer_handler(void)
-{
-/*
- * Here we are in the timer irq handler. We have irqs locally disabled (so we
- * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
- * on the other CPU, so we need a lock. We also need to lock the vsyscall
- * variables, because both do_timer() and us change them -arca+vojtech
- */
-
-       write_seqlock(&xtime_lock);
-
-/*
- * Do the timer stuff.
- */
-
-       do_timer(1);
-#ifndef CONFIG_SMP
-       update_process_times(user_mode(get_irq_regs()));
-#endif
-
-/*
- * In the SMP case we use the local APIC timer interrupt to do the profiling,
- * except when we simulate SMP mode on a uniprocessor system, in that case we
- * have to call the local interrupt handler.
- */
-
-       if (!using_apic_timer)
-               smp_local_timer_interrupt();
-
-       write_sequnlock(&xtime_lock);
-}
-
-static irqreturn_t timer_interrupt(int irq, void *dev_id)
-{
-       if (apic_runs_main_timer > 1)
-               return IRQ_HANDLED;
-       main_timer_handler();
-       if (using_apic_timer)
-               smp_send_timer_broadcast_ipi();
-       return IRQ_HANDLED;
-}
-
 static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
 {
        add_pda(irq0_irqs, 1);