[patch -mm 19/28] x86_64: Use generic cmos update

Thomas Gleixner
2007-06-23T13:28:25Z

[-- Attachment #1: x86-64-use-generic-cmos-update.patch --]
[-- Type: text/plain, Size: 2897 bytes --]

Use the generic cmos update function in kernel/time/ntp.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>

---
arch/x86_64/Kconfig | 4 ++++
arch/x86_64/kernel/time.c | 25 +++++++++----------------
2 files changed, 13 insertions(+), 16 deletions(-)

Index: linux-2.6.22-rc4-mm/arch/x86_64/kernel/time.c
===================================================================
--- linux-2.6.22-rc4-mm.orig/arch/x86_64/kernel/time.c 2007-06-23 14:38:58.000000000 +0200
+++ linux-2.6.22-rc4-mm/arch/x86_64/kernel/time.c 2007-06-23 14:38:59.000000000 +0200
@@ -82,8 +82,9 @@ 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;

@@ -123,6 +124,7 @@ 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);
@@ -142,12 +144,17 @@ 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
@@ -175,20 +182,6 @@ 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);
}

Index: linux-2.6.22-rc4-mm/arch/x86_64/Kconfig
===================================================================
--- linux-2.6.22-rc4-mm.orig/arch/x86_64/Kconfig 2007-06-23 14:38:55.000000000 +0200
+++ linux-2.6.22-rc4-mm/arch/x86_64/Kconfig 2007-06-23 14:38:59.000000000 +0200
@@ -32,6 +32,10 @@ config GENERIC_TIME_VSYSCALL
bool
default y

+config GENERIC_CMOS_UPDATE
+ bool
+ default y
+
config ZONE_DMA32
bool
default y

--