diff options
Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r-- | arch/x86_64/kernel/time.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 335cc91c49b7..9c7fba30dac1 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c | |||
@@ -657,6 +657,7 @@ core_initcall(cpufreq_tsc); | |||
657 | 657 | ||
658 | #define TICK_COUNT 100000000 | 658 | #define TICK_COUNT 100000000 |
659 | #define TICK_MIN 5000 | 659 | #define TICK_MIN 5000 |
660 | #define MAX_READ_RETRIES 5 | ||
660 | 661 | ||
661 | /* | 662 | /* |
662 | * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none | 663 | * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none |
@@ -664,13 +665,17 @@ core_initcall(cpufreq_tsc); | |||
664 | */ | 665 | */ |
665 | static void __init read_hpet_tsc(int *hpet, int *tsc) | 666 | static void __init read_hpet_tsc(int *hpet, int *tsc) |
666 | { | 667 | { |
667 | int tsc1, tsc2, hpet1; | 668 | int tsc1, tsc2, hpet1, retries = 0; |
669 | static int msg; | ||
668 | 670 | ||
669 | do { | 671 | do { |
670 | tsc1 = get_cycles_sync(); | 672 | tsc1 = get_cycles_sync(); |
671 | hpet1 = hpet_readl(HPET_COUNTER); | 673 | hpet1 = hpet_readl(HPET_COUNTER); |
672 | tsc2 = get_cycles_sync(); | 674 | tsc2 = get_cycles_sync(); |
673 | } while (tsc2 - tsc1 > TICK_MIN); | 675 | } while (tsc2 - tsc1 > TICK_MIN && retries++ < MAX_READ_RETRIES); |
676 | if (retries >= MAX_READ_RETRIES && !msg++) | ||
677 | printk(KERN_WARNING | ||
678 | "hpet.c: exceeded max retries to read HPET & TSC\n"); | ||
674 | *hpet = hpet1; | 679 | *hpet = hpet1; |
675 | *tsc = tsc2; | 680 | *tsc = tsc2; |
676 | } | 681 | } |