+#define CLOCK_TICK_FACTOR 20 /* Factor of both 1000000 and CLOCK_TICK_RATE */
+#define FINETUNE ((((((int)LATCH * HZ - CLOCK_TICK_RATE) << SHIFT_HZ) * \
+ (1000000/CLOCK_TICK_FACTOR) / (CLOCK_TICK_RATE/CLOCK_TICK_FACTOR)) \
+ << (SHIFT_SCALE-SHIFT_HZ)) / HZ)