+
+success:
+ /*
+ * Ok, if we get here, then we've seen the
+ * MSB of the PIT decrement 'i' times, and the
+ * error has shrunk to less than 500 ppm.
+ *
+ * As a result, we can depend on there not being
+ * any odd delays anywhere, and the TSC reads are
+ * reliable (within the error). We also adjust the
+ * delta to the middle of the error bars, just
+ * because it looks nicer.
+ *
+ * kHz = ticks / time-in-seconds / 1000;
+ * kHz = (t2 - t1) / (I * 256 / PIT_TICK_RATE) / 1000
+ * kHz = ((t2 - t1) * PIT_TICK_RATE) / (I * 256 * 1000)
+ */
+ delta += (long)(d2 - d1)/2;
+ delta *= PIT_TICK_RATE;
+ do_div(delta, i*256*1000);
+ printk("Fast TSC calibration using PIT\n");
+ return delta;