/**
 * lib/minmax.c: windowed min/max tracker
 *
 * Kathleen Nichols' algorithm for tracking the minimum (or maximum)
 * value of a data stream over some fixed time interval.  (E.g.,
 * the minimum RTT over the past five minutes.) It uses constant
 * space and constant time per update yet almost always delivers
 * the same minimum as an implementation that has to keep all the
 * data in the window.
 *
 * The algorithm keeps track of the best, 2nd best & 3rd best min
 * values, maintaining an invariant that the measurement time of
 * the n'th best >= n-1'th best. It also makes sure that the three
 * values are widely separated in the time window since that bounds
 * the worse case error when that data is monotonically increasing
 * over the window.
 *
 * Upon getting a new min, we can forget everything earlier because
 * it has no value - the new min is <= everything else in the window
 * by definition and it's the most recent. So we restart fresh on
 * every new min and overwrites 2nd & 3rd choices. The same property
 * holds for 2nd & 3rd best.
 */
#include <linux/module.h>
#include <linux/win_minmax.h>

/* As time advances, update the 1st, 2nd, and 3rd choices. */
static u32 minmax_subwin_update(struct minmax *m, u32 win,
				const struct minmax_sample *val)
{
	u32 dt = val->t - m->s[0].t;

	if (unlikely(dt > win)) {
		/*
		 * Passed entire window without a new val so make 2nd
		 * choice the new val & 3rd choice the new 2nd choice.
		 * we may have to iterate this since our 2nd choice
		 * may also be outside the window (we checked on entry
		 * that the third choice was in the window).
		 */
		m->s[0] = m->s[1];
		m->s[1] = m->s[2];
		m->s[2] = *val;
		if (unlikely(val->t - m->s[0].t > win)) {
			m->s[0] = m->s[1];
			m->s[1] = m->s[2];
			m->s[2] = *val;
		}
	} else if (unlikely(m->s[1].t == m->s[0].t) && dt > win/4) {
		/*
		 * We've passed a quarter of the window without a new val
		 * so take a 2nd choice from the 2nd quarter of the window.
		 */
		m->s[2] = m->s[1] = *val;
	} else if (unlikely(m->s[2].t == m->s[1].t) && dt > win/2) {
		/*
		 * We've passed half the window without finding a new val
		 * so take a 3rd choice from the last half of the window
		 */
		m->s[2] = *val;
	}
	return m->s[0].v;
}

/* Check if new measurement updates the 1st, 2nd or 3rd choice max. */
u32 minmax_running_max(struct minmax *m, u32 win, u32 t, u32 meas)
{
	struct minmax_sample val = { .t = t, .v = meas };

	if (unlikely(val.v >= m->s[0].v) ||	  /* found new max? */
	    unlikely(val.t - m->s[2].t > win))	  /* nothing left in window? */
		return minmax_reset(m, t, meas);  /* forget earlier samples */

	if (unlikely(val.v >= m->s[1].v))
		m->s[2] = m->s[1] = val;
	else if (unlikely(val.v >= m->s[2].v))
		m->s[2] = val;

	return minmax_subwin_update(m, win, &val);
}
EXPORT_SYMBOL(minmax_running_max);

/* Check if new measurement updates the 1st, 2nd or 3rd choice min. */
u32 minmax_running_min(struct minmax *m, u32 win, u32 t, u32 meas)
{
	struct minmax_sample val = { .t = t, .v = meas };

	if (unlikely(val.v <= m->s[0].v) ||	  /* found new min? */
	    unlikely(val.t - m->s[2].t > win))	  /* nothing left in window? */
		return minmax_reset(m, t, meas);  /* forget earlier samples */

	if (unlikely(val.v <= m->s[1].v))
		m->s[2] = m->s[1] = val;
	else if (unlikely(val.v <= m->s[2].v))
		m->s[2] = val;

	return minmax_subwin_update(m, win, &val);
}
b><form method='get'><input type='hidden' name='id' value='0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Olof Johansson &lt;olof@lixom.net&gt;</td><td class='right'>2017-01-29 21:00:48 -0800</td></tr>
<tr><th>committer</th><td>Olof Johansson &lt;olof@lixom.net&gt;</td><td class='right'>2017-01-29 21:00:48 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/codecs/cs35l33.c?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>0a019a28e0ca0af7dc2691d1a9527960b07ad2bb</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/soc/codecs/cs35l33.c?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>5ee1db9aacacd6af6701fb290e8a294ef3cc2bf2</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/soc/codecs/cs35l33.c?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>sound/soc/codecs/cs35l33.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/codecs/cs35l33.c?id=ec026b5020688a8bde5fae9a69ae3c59b66ba3ae'>ec026b5020688a8bde5fae9a69ae3c59b66ba3ae</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/codecs/cs35l33.c?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb&amp;id2=ec026b5020688a8bde5fae9a69ae3c59b66ba3ae'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/codecs/cs35l33.c?id=8413299cb3933dade6186bbee8363f190032107e'>8413299cb3933dade6186bbee8363f190032107e</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/codecs/cs35l33.c?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb&amp;id2=8413299cb3933dade6186bbee8363f190032107e'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'sti-dt-for-v4.10-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/pchotard/sti into fixes</div><div class='commit-msg'>STi DT fix:

Since v4.10-rc1, xhci is complaining in loop with :
    [  801.953836] usb usb6-port1: Cannot enable. Maybe the USB cable is bad?
    [  801.960455] xhci-hcd xhci-hcd.0.auto: Cannot set link state.
    [  801.966611] usb usb6-port1: cannot disable (err = -32)

set property "snps,dis_u3_susphy_quirk" in DT fix it.

* tag 'sti-dt-for-v4.10-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/pchotard/sti:
  ARM: dts: STiH407-family: set snps,dis_u3_susphy_quirk

Signed-off-by: Olof Johansson &lt;olof@lixom.net&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>Diffstat</a> (limited to 'sound/soc/codecs/cs35l33.c')</div><table summary='diffstat' class='diffstat'>