diff options
| author | Linus Torvalds <torvalds@woody.osdl.org> | 2007-01-10 18:06:14 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2007-01-10 18:06:14 -0800 |
| commit | 0404f87f2e0a0aadbda47be0f54812671207492f (patch) | |
| tree | 388ed26f2508aa0188d9435ee0e5a7a7786f8793 /arch/x86_64/kernel/time.c | |
| parent | 2d9819e3473f3e2200a4942760fa1f3d41043b99 (diff) | |
| parent | 7401969907594ac9632368ec53528fbd9b18f339 (diff) | |
Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6:
[PATCH] x86-64: Fix warnings in ia32_aout.c
[PATCH] i386: Convert some functions to __init to avoid MODPOST warnings
[PATCH] i386: Fix memory hotplug related MODPOST generated warning
[PATCH] x86-64: tighten up printks
[PATCH] x86-64: - Ignore long SMI interrupts in clock calibration
[PATCH] x86-64: pci quirks MODPOST warning fix
[PATCH] x86-64: Modpost whitelist reference to more symbols (pattern 3)
[PATCH] x86-64: modpost add more symbols to whitelist pattern2
[PATCH] i386: make apic probe function non-init
[PATCH] i386: cpu hotplug/smpboot misc MODPOST warning fixes
[PATCH] x86-64: Use different constraint for gcc < 4.1 in bitops.h
[PATCH] x86-64: Make noirqdebug_setup function non init to fix modpost warning
[PATCH] i386: Update defconfig
[PATCH] x86-64: Update defconfig
Diffstat (limited to 'arch/x86_64/kernel/time.c')
| -rw-r--r-- | arch/x86_64/kernel/time.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 9f05bc9b2da..5cc76d0d331 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -656,6 +656,25 @@ core_initcall(cpufreq_tsc); */ #define TICK_COUNT 100000000 +#define TICK_MIN 5000 + +/* + * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none + * occurs between the reads of the hpet & TSC. + */ +static void __init read_hpet_tsc(int *hpet, int *tsc) +{ + int tsc1, tsc2, hpet1; + + do { + tsc1 = get_cycles_sync(); + hpet1 = hpet_readl(HPET_COUNTER); + tsc2 = get_cycles_sync(); + } while (tsc2 - tsc1 > TICK_MIN); + *hpet = hpet1; + *tsc = tsc2; +} + static unsigned int __init hpet_calibrate_tsc(void) { @@ -666,13 +685,11 @@ static unsigned int __init hpet_calibrate_tsc(void) local_irq_save(flags); local_irq_disable(); - hpet_start = hpet_readl(HPET_COUNTER); - rdtscl(tsc_start); + read_hpet_tsc(&hpet_start, &tsc_start); do { local_irq_disable(); - hpet_now = hpet_readl(HPET_COUNTER); - tsc_now = get_cycles_sync(); + read_hpet_tsc(&hpet_now, &tsc_now); local_irq_restore(flags); } while ((tsc_now - tsc_start) < TICK_COUNT && (hpet_now - hpet_start) < TICK_COUNT); |