From: Thomas Gleixner <tglx@linutronix.de>
Use the generic cmos update function in kernel/time/ntp.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
---
arch/x86_64/Kconfig | 4 ++++
arch/x86_64/kernel/time.c | 25 +++++++++----------------
2 files changed, 13 insertions(+), 16 deletions(-)
Index: linux/arch/x86_64/Kconfig
===================================================================
--- linux.orig/arch/x86_64/Kconfig
+++ linux/arch/x86_64/Kconfig
@@ -32,6 +32,10 @@ config GENERIC_TIME_VSYSCALL
bool
default y
+config GENERIC_CMOS_UPDATE
+ bool
+ default y
+
config ZONE_DMA32
bool
default y
Index: linux/arch/x86_64/kernel/time.c
===================================================================
--- linux.orig/arch/x86_64/kernel/time.c
+++ linux/arch/x86_64/kernel/time.c
@@ -80,8 +80,9 @@ EXPORT_SYMBOL(profile_pc);
* sheet for details.
*/
-static void set_rtc_mmss(unsigned long nowtime)
+static int set_rtc_mmss(unsigned long nowtime)
{
+ int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
unsigned char control, freq_select;
@@ -121,6 +122,7 @@ static void set_rtc_mmss(unsigned long n
if (abs(real_minutes - cmos_minutes) >= 30) {
printk(KERN_WARNING "time.c: can't update CMOS clock "
"from %d to %d\n", cmos_minutes, real_minutes);
+ retval = -1;
} else {
BIN_TO_BCD(real_seconds);
BIN_TO_BCD(real_minutes);
@@ -140,12 +142,17 @@ static void set_rtc_mmss(unsigned long n
CMOS_WRITE(freq_select, RTC_FREQ_SELECT);
spin_unlock(&rtc_lock);
+
+ return retval;
}
+int update_persistent_clock(struct timespec now)
+{
+ return set_rtc_mmss(now.tv_sec);
+}
void main_timer_handler(void)
{
- static unsigned long rtc_update = 0;
/*
* 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
@@ -173,20 +180,6 @@ void main_timer_handler(void)
if (!using_apic_timer)
smp_local_timer_interrupt();
-/*
- * If we have an externally synchronized Linux clock, then update CMOS clock
- * accordingly every ~11 minutes. set_rtc_mmss() will be called in the jiffy
- * closest to exactly 500 ms before the next second. If the update fails, we
- * don't care, as it'll be updated on the next turn, and the problem (time way
- * off) isn't likely to go away much sooner anyway.
- */
-
- if (ntp_synced() && xtime.tv_sec > rtc_update &&
- abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2) {
- set_rtc_mmss(xtime.tv_sec);
- rtc_update = xtime.tv_sec + 660;
- }
-
write_sequnlock(&xtime_lock);
}
-
