aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/hpet.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 13:18:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 13:18:29 -0700
commitb62ad9ab181a67207a4c8c373461b587c4861a68 (patch)
treeace1572964d81f5f9bbc10b7960c1f742832d744 /arch/x86/kernel/hpet.c
parentaf390084359a5de20046c901529b2b6a50b941cb (diff)
parentb29230769e3482bbd62a07d6d9485371ee66a18f (diff)
Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: um: Fix read_persistent_clock fallout kgdb: Do not access xtime directly powerpc: Clean up obsolete code relating to decrementer and timebase powerpc: Rework VDSO gettimeofday to prevent time going backwards clocksource: Add __clocksource_updatefreq_hz/khz methods x86: Convert common clocksources to use clocksource_register_hz/khz timekeeping: Make xtime and wall_to_monotonic static hrtimer: Cleanup direct access to wall_to_monotonic um: Convert to use read_persistent_clock timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset powerpc: Cleanup xtime usage powerpc: Simplify update_vsyscall time: Kill off CONFIG_GENERIC_TIME time: Implement timespec_add x86: Fix vtime/file timestamp inconsistencies Trivial conflicts in Documentation/feature-removal-schedule.txt Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as per Thomas' earlier merge commit 47916be4e28c ("Merge branch 'powerpc.cherry-picks' into timers/clocksource")
Diffstat (limited to 'arch/x86/kernel/hpet.c')
-rw-r--r--arch/x86/kernel/hpet.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ba390d73117..33dbcc4ec5f 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -16,7 +16,6 @@
#include <asm/hpet.h>
#define HPET_MASK CLOCKSOURCE_MASK(32)
-#define HPET_SHIFT 22
/* FSEC = 10^-15
NSEC = 10^-9 */
@@ -787,7 +786,6 @@ static struct clocksource clocksource_hpet = {
.rating = 250,
.read = read_hpet,
.mask = HPET_MASK,
- .shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = hpet_resume_counter,
#ifdef CONFIG_X86_64
@@ -798,6 +796,7 @@ static struct clocksource clocksource_hpet = {
static int hpet_clocksource_register(void)
{
u64 start, now;
+ u64 hpet_freq;
cycle_t t1;
/* Start the counter */
@@ -832,9 +831,15 @@ static int hpet_clocksource_register(void)
* mult = (hpet_period * 2^shift)/10^6
* mult = (hpet_period << shift)/FSEC_PER_NSEC
*/
- clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
- clocksource_register(&clocksource_hpet);
+ /* Need to convert hpet_period (fsec/cyc) to cyc/sec:
+ *
+ * cyc/sec = FSEC_PER_SEC/hpet_period(fsec/cyc)
+ * cyc/sec = (FSEC_PER_NSEC * NSEC_PER_SEC)/hpet_period
+ */
+ hpet_freq = FSEC_PER_NSEC * NSEC_PER_SEC;
+ do_div(hpet_freq, hpet_period);
+ clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
return 0;
}