65  * suffix array, log interval and exponential moving average
84  * 2. Log interval
86  * We saw the irq timings allow to compute the interval of the
88  * longer is the interval, the higher is the error for the next event
89  * and we can consider storing those interval values into an array
90  * where each slot in the array correspond to an interval at the power
95  * [2^index - 1, 2 ^ index] interval values allowing to store a large
116  * interval, we can have numbers with a big difference between
127  *	For each interval:
128  *		Compute the index = ilog2(interval)
129  *		Compute a new_ema(buffer[index], interval)
150  * Example 1 : MMC write/read interrupt interval:
206  * interval is ema[8] = 1366
312 	 * interrupt interval (292 years).  in irq_timings_ema_new()
435 static __always_inline int irq_timings_interval_index(u64 interval)  in irq_timings_interval_index()  argument
438 	 * The PREDICTION_FACTOR increase the interval size for the  in irq_timings_interval_index()
441 	u64 interval_us = (interval >> 10) / PREDICTION_FACTOR;  in irq_timings_interval_index()
447 						u64 interval)  in __irq_timings_store()  argument
454 	index = irq_timings_interval_index(interval);  in __irq_timings_store()
467 	irqs->ema_time[index] = irq_timings_ema_new(interval,  in __irq_timings_store()
476 	u64 interval;  in irq_timings_store()  local
480 	 * the timing interval between two interrupts.  in irq_timings_store()
485 	 * The interval type is u64 in order to deal with the same  in irq_timings_store()
489 	interval = ts - old_ts;  in irq_timings_store()
500 	 * want as we need another timestamp to compute an interval.  in irq_timings_store()
502 	if (interval >= NSEC_PER_SEC) {  in irq_timings_store()
507 	__irq_timings_store(irq, irqs, interval);  in irq_timings_store()
798 		pr_debug("%d: interval=%llu ema_index=%d\n",  in irq_timings_test_irqs()