From c70a23f7a893c5787f365df34ba240dac34e92bf Mon Sep 17 00:00:00 2001
From: Tim Wilkinson <tim.j.wilkinson@gmail.com>
Date: Sat, 11 Feb 2023 11:43:36 -0800
Subject: [PATCH] Improve LQM distance management 02/11/2023 (#705)

---
 files/usr/local/bin/mgr/lqm.lua | 44 +++++++++++++++------------------
 1 file changed, 20 insertions(+), 24 deletions(-)

diff --git a/files/usr/local/bin/mgr/lqm.lua b/files/usr/local/bin/mgr/lqm.lua
index 3e61af86..6189f718 100755
--- a/files/usr/local/bin/mgr/lqm.lua
+++ b/files/usr/local/bin/mgr/lqm.lua
@@ -247,6 +247,7 @@ function lqm()
     local dtdlinks = {}
     local rflinks = {}
     local hidden_nodes = {}
+    local last_coverage = -1
     while true
     do
         now = nixio.sysinfo().uptime
@@ -506,10 +507,6 @@ function lqm()
             end
         end
 
-        local distance = -1
-        local alt_distance = -1
-        local coverage = -1
-
         -- Count the RF links we have
         local rfcount = 0
         for _, track in pairs(tracker)
@@ -816,6 +813,8 @@ function lqm()
             end
         end
 
+        local distance = -1
+
         -- Update the block state and calculate the routable distance
         for _, track in pairs(tracker)
         do
@@ -825,16 +824,14 @@ function lqm()
                     track.pending = now + pending_timeout
                 end
 
-                -- Find the most distant, unblocked, routable, RF node
-                if track.type == "RF" and not track.blocked and track.distance then
-                    if not is_pending(track) and track.routable then
-                        if track.distance > distance then 
+                -- Find the most distant, unblocked, RF node
+                if track.type == "RF" then
+                    if track.distance then
+                        if track.distance > distance and (not track.blocked or is_pending(track)) then
                             distance = track.distance
                         end
-                    else
-                        if track.distance > alt_distance then
-                            alt_distance = track.distance
-                        end
+                    elseif is_pending(track) then
+                        distance = config.max_distance
                     end
                 end
             end
@@ -846,20 +843,19 @@ function lqm()
             end
         end
 
-        distance = distance + 1
-        alt_distance = alt_distance + 1
-
+        -- Default distances if we haven't calcuated anything
+        if distance < 0 then
+            if config.auto_distance > 0 then
+                distance = config.auto_distance
+            else
+                distance = config.max_distance
+            end
+        end
         -- Update the wifi distance
-        if distance > 0 then
-            coverage = math.min(255, math.floor((distance * 2 * 0.0033) / 3)) -- airtime
+        local coverage = math.min(255, math.floor((distance * 2 * 0.0033) / 3))
+        if coverage ~= last_coverage then
             os.execute(IW .. " " .. phy .. " set coverage " .. coverage .. " > /dev/null 2>&1")
-        elseif alt_distance > 1 then
-            coverage = math.min(255, math.floor((alt_distance * 2 * 0.0033) / 3))
-            os.execute(IW .. " " .. phy .. " set coverage " .. coverage .. " > /dev/null 2>&1")
-        elseif config.auto_distance > 0 then
-            os.execute(IW .. " " .. phy .. " set distance " .. config.auto_distance .. " > /dev/null 2>&1")
-        else
-            os.execute(IW .. " " .. phy .. " set distance auto > /dev/null 2>&1")
+            last_coverage = coverage
         end
 
         -- Set the RTS/CTS state depending on whether everyone can see everyone