Add an auto-measure toggle with a cable length range, and console keys through the harness

phy.go

@@ -267,7 +267,7 @@ type cableInfo struct {
 	haveMaps [2]bool
 }
 
-func (c cableInfo) metresString() string {
+func (c cableInfo) metresValue() (int, bool) {
 	sum, n := 0, 0
 	for i, v := range c.ecd.verdicts {
 		if v == pairOK {
@@ -276,9 +276,39 @@ func (c cableInfo) metresString() string {
 		}
 	}
 	if n == 0 {
+		return 0, false
+	}
+	return (sum + n/2) / n, true
+}
+
+func (c cableInfo) metresString() string {
+	m, ok := c.metresValue()
+	if !ok {
 		return "-"
 	}
-	return fmt.Sprintf("%d", (sum+n/2)/n)
+	return fmt.Sprintf("%d", m)
+}
+
+type cableRange struct {
+	have     bool
+	min, max int
+}
+
+func (r *cableRange) add(m int) {
+	if !r.have || m < r.min {
+		r.min = m
+	}
+	if !r.have || m > r.max {
+		r.max = m
+	}
+	r.have = true
+}
+
+func (r cableRange) String() string {
+	if r.min == r.max {
+		return fmt.Sprintf("%d", r.min)
+	}
+	return fmt.Sprintf("%d-%d", r.min, r.max)
 }
 
 const (
@@ -348,7 +378,7 @@ func cableSummary(cable cableInfo, measuring bool) (string, int) {
 
 // The margin is the worst pair across the ends that measure SNR (the Wiitek's
 // IEEE 1.133–136), gated on the whole pair being fresh and linked.
-func phyDisplayFrom(cable cableInfo, measuring bool, a, b phyModView) phyDisplay {
+func phyDisplayFrom(cable cableInfo, rng cableRange, measuring bool, a, b phyModView) phyDisplay {
 	d := phyDisplay{
 		haveSNR:   a.fresh && b.fresh && a.link && b.link && (a.haveSNR || b.haveSNR),
 		corrected: a.blocks + a.ber + a.retrain + b.blocks + b.ber + b.retrain,
@@ -369,6 +399,9 @@ func phyDisplayFrom(cable cableInfo, measuring bool, a, b phyModView) phyDisplay
 		}
 	}
 	d.metres, d.metresClass = cableSummary(cable, measuring)
+	if d.metresClass == clsGood && rng.have {
+		d.metres = rng.String()
+	}
 	return d
 }
 
@@ -444,16 +477,23 @@ type cableDiag struct {
 
 	mu   sync.Mutex
 	info cableInfo
+	rng  cableRange
 }
 
 func newCableDiag(mods []*phyModule, info cableInfo) *cableDiag {
 	return &cableDiag{mods: mods, info: info}
 }
 
-func (c *cableDiag) snapshot() (cableInfo, bool) {
+func (c *cableDiag) snapshot() (cableInfo, cableRange, bool) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	return c.info, c.measuring.Load()
+	return c.info, c.rng, c.measuring.Load()
+}
+
+func (c *cableDiag) resetRange() {
+	c.mu.Lock()
+	c.rng = cableRange{}
+	c.mu.Unlock()
 }
 
 // A measure that errors means the diag transport or the µC is broken, and a
@@ -471,6 +511,11 @@ func (c *cableDiag) kick(done *atomic.Bool) bool {
 		}
 		c.mu.Lock()
 		c.info = info
+		if _, cls := cableSummary(info, false); cls == clsGood {
+			if m, ok := info.metresValue(); ok {
+				c.rng.add(m)
+			}
+		}
 		c.mu.Unlock()
 		c.measuring.Store(false)
 	}()