diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index d78444c788a3..f04d08a7d022 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -131,7 +131,7 @@ unsigned long native_calculate_cpu_khz(void)
 {
 	unsigned long long start, end;
 	unsigned long count;
-	u64 delta64;
+	u64 delta64 = (u64)ULLONG_MAX;
 	int i;
 	unsigned long flags;
 
@@ -143,6 +143,7 @@ unsigned long native_calculate_cpu_khz(void)
 		rdtscll(start);
 		mach_countup(&count);
 		rdtscll(end);
+		delta64 = min(delta64, (end - start));
 	}
 	/*
 	 * Error: ECTCNEVERSET
@@ -153,8 +154,6 @@ unsigned long native_calculate_cpu_khz(void)
 	if (count <= 1)
 		goto err;
 
-	delta64 = end - start;
-
 	/* cpu freq too fast: */
 	if (delta64 > (1ULL<<32))
 		goto err;