summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/tsc.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r--arch/x86/kernel/tsc.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 505449700e0c..7437b41f6a47 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -598,10 +598,19 @@ static unsigned long quick_pit_calibrate(void)
if (!pit_expect_msb(0xff-i, &delta, &d2))
break;
+ delta -= tsc;
+
+ /*
+ * Extrapolate the error and fail fast if the error will
+ * never be below 500 ppm.
+ */
+ if (i == 1 &&
+ d1 + d2 >= (delta * MAX_QUICK_PIT_ITERATIONS) >> 11)
+ return 0;
+
/*
* Iterate until the error is less than 500 ppm
*/
- delta -= tsc;
if (d1+d2 >= delta >> 11)
continue;