path: root/arch/x86/kernel/rtc.c
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2013-04-30 08:15:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-30 08:15:40 -0700
commitab86e974f04b1cd827a9c7c35273834ebcd9ab38 (patch)
tree41df33732d2700d6d57d1e7ab3f430942f09ffcc /arch/x86/kernel/rtc.c
parent8700c95adb033843fc163d112b9d21d4fda78018 (diff)
parent6f7a05d7018de222e40ca003721037a530979974 (diff)
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core timer updates from Ingo Molnar: "The main changes in this cycle's merge are: - Implement shadow timekeeper to shorten in kernel reader side blocking, by Thomas Gleixner. - Posix timers enhancements by Pavel Emelyanov: - allocate timer ID per process, so that exact timer ID allocations can be re-created be checkpoint/restore code. - debuggability and tooling (/proc/PID/timers, etc.) improvements. - suspend/resume enhancements by Feng Tang: on certain new Intel Atom processors (Penwell and Cloverview), there is a feature that the TSC won't stop in S3 state, so the TSC value won't be reset to 0 after resume. This can be taken advantage of by the generic via the CLOCK_SOURCE_SUSPEND_NONSTOP flag: instead of using the RTC to recover/approximate sleep time, the main (and precise) clocksource can be used. - Fix /proc/timer_list for 4096 CPUs by Nathan Zimmer: on so many CPUs the file goes beyond 4MB of size and thus the current simplistic seqfile approach fails. Convert /proc/timer_list to a proper seq_file with its own iterator. - Cleanups and refactorings of the core timekeeping code by John Stultz. - International Atomic Clock time is managed by the NTP code internally currently but not exposed externally. Separate the TAI code out and add CLOCK_TAI support and TAI support to the hrtimer and posix-timer code, by John Stultz. - Add deep idle support enhacement to the broadcast clockevents core timer code, by Daniel Lezcano: add an opt-in CLOCK_EVT_FEAT_DYNIRQ clockevents feature (which will be utilized by future clockevents driver updates), which allows the use of IRQ affinities to avoid spurious wakeups of idle CPUs - the right CPU with an expiring timer will be woken. - Add new ARM bcm281xx clocksource driver, by Christian Daudt - ... various other fixes and cleanups" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) clockevents: Set dummy handler on CPU_DEAD shutdown timekeeping: Update tk->cycle_last in resume posix-timers: Remove unused variable clockevents: Switch into oneshot mode even if broadcast registered late timer_list: Convert timer list to be a proper seq_file timer_list: Split timer_list_show_tickdevices posix-timers: Show sigevent info in proc file posix-timers: Introduce /proc/PID/timers file posix timers: Allocate timer id per process (v2) timekeeping: Make sure to notify hrtimers when TAI offset changes hrtimer: Fix ktime_add_ns() overflow on 32bit architectures hrtimer: Add expiry time overflow check in hrtimer_interrupt timekeeping: Shorten seq_count region timekeeping: Implement a shadow timekeeper timekeeping: Delay update of clock->cycle_last timekeeping: Store cycle_last value in timekeeper struct as well ntp: Remove ntp_lock, using the timekeeping locks to protect ntp state timekeeping: Simplify tai updating from do_adjtimex timekeeping: Hold timekeepering locks in do_adjtimex and hardpps timekeeping: Move ADJ_SETOFFSET to top level do_adjtimex() ...
Diffstat (limited to 'arch/x86/kernel/rtc.c')
1 files changed, 12 insertions, 57 deletions
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 2e8f3d3b564..198eb201ed3 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -13,6 +13,7 @@
#include <asm/x86_init.h>
#include <asm/time.h>
#include <asm/mrst.h>
+#include <asm/rtc.h>
#ifdef CONFIG_X86_32
@@ -36,70 +37,24 @@ EXPORT_SYMBOL(rtc_lock);
* nowtime is written into the registers of the CMOS clock, it will
* jump to the next second precisely 500 ms later. Check the Motorola
* MC146818A or Dallas DS12887 data sheet for details.
- *
- * BUG: This routine does not handle hour overflow properly; it just
- * sets the minutes. Usually you'll only notice that after reboot!
int mach_set_rtc_mmss(unsigned long nowtime)
- int real_seconds, real_minutes, cmos_minutes;
- unsigned char save_control, save_freq_select;
- unsigned long flags;
+ struct rtc_time tm;
int retval = 0;
- spin_lock_irqsave(&rtc_lock, flags);
- /* tell the clock it's being set */
- save_control = CMOS_READ(RTC_CONTROL);
- CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
- /* stop and reset prescaler */
- save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
- cmos_minutes = CMOS_READ(RTC_MINUTES);
- if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
- cmos_minutes = bcd2bin(cmos_minutes);
- /*
- * since we're only adjusting minutes and seconds,
- * don't interfere with hour overflow. This avoids
- * messing with unknown time zones but requires your
- * RTC not to be off by more than 15 minutes
- */
- real_seconds = nowtime % 60;
- real_minutes = nowtime / 60;
- /* correct for half hour time zone */
- if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
- real_minutes += 30;
- real_minutes %= 60;
- if (abs(real_minutes - cmos_minutes) < 30) {
- if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
- real_seconds = bin2bcd(real_seconds);
- real_minutes = bin2bcd(real_minutes);
- }
- CMOS_WRITE(real_seconds, RTC_SECONDS);
- CMOS_WRITE(real_minutes, RTC_MINUTES);
+ rtc_time_to_tm(nowtime, &tm);
+ if (!rtc_valid_tm(&tm)) {
+ retval = set_rtc_time(&tm);
+ if (retval)
+ printk(KERN_ERR "%s: RTC write failed with error %d\n",
+ __FUNCTION__, retval);
} else {
- printk_once(KERN_NOTICE
- "set_rtc_mmss: can't update from %d to %d\n",
- cmos_minutes, real_minutes);
- retval = -1;
+ printk(KERN_ERR
+ "%s: Invalid RTC value: write of %lx to RTC failed\n",
+ __FUNCTION__, nowtime);
+ retval = -EINVAL;
- /* The following flags have to be released exactly in this order,
- * otherwise the DS12887 (popular MC146818A clone with integrated
- * battery and quartz) will not reset the oscillator and will not
- * update precisely 500 ms later. You won't find this mentioned in
- * the Dallas Semiconductor data sheets, but who believes data
- * sheets anyway ... -- Markus Kuhn
- */
- CMOS_WRITE(save_control, RTC_CONTROL);
- CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
- spin_unlock_irqrestore(&rtc_lock, flags);
return retval;