From d004cf5fb718e1830b0ee1e48d2786a96c3529a6 Mon Sep 17 00:00:00 2001
From: codecae <codecae@users.noreply.github.com>
Date: Mon, 5 Mar 2018 14:27:50 -0500
Subject: [PATCH] Improved VTX update scheduling to reduce update delays
 (#5340)

---
 src/main/io/vtx.c | 44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/src/main/io/vtx.c b/src/main/io/vtx.c
index de2be71d17..465cc9cd63 100644
--- a/src/main/io/vtx.c
+++ b/src/main/io/vtx.c
@@ -218,30 +218,34 @@ void vtxUpdate(timeUs_t currentTimeUs)
         // Check input sources for config updates
         vtxControlInputPoll();
 
+        const uint8_t startingSchedule = currentSchedule;
         bool vtxUpdatePending = false;
-        switch (currentSchedule) {
-        case VTX_PARAM_POWER:
-            vtxUpdatePending = vtxProcessPower(vtxDevice);
-            break;
-        case VTX_PARAM_BANDCHAN:
-            if (vtxGetSettings().band) {
-                vtxUpdatePending = vtxProcessBandAndChannel(vtxDevice);
+        do {
+            switch (currentSchedule) {
+                case VTX_PARAM_POWER:
+                    vtxUpdatePending = vtxProcessPower(vtxDevice);
+                    break;
+                case VTX_PARAM_BANDCHAN:
+                    if (vtxGetSettings().band) {
+                        vtxUpdatePending = vtxProcessBandAndChannel(vtxDevice);
 #if defined(VTX_SETTINGS_FREQCMD)
-            } else {
-                vtxUpdatePending = vtxProcessFrequency(vtxDevice);
+                    } else {
+                        vtxUpdatePending = vtxProcessFrequency(vtxDevice);
 #endif
+                    }
+                    break;
+                case VTX_PARAM_PITMODE:
+                    vtxUpdatePending = vtxProcessPitMode(vtxDevice);
+                    break;
+                case VTX_PARAM_CONFIRM:
+                    vtxUpdatePending = vtxProcessStateUpdate(vtxDevice);
+                    break;
+                default:
+                    break;
             }
-            break;
-        case VTX_PARAM_PITMODE:
-            vtxUpdatePending = vtxProcessPitMode(vtxDevice);
-            break;
-        case VTX_PARAM_CONFIRM:
-            vtxUpdatePending = vtxProcessStateUpdate(vtxDevice);
-            break;
-        default:
-            break;
-        }
-        currentSchedule = (currentSchedule + 1) % VTX_PARAM_COUNT;
+            currentSchedule = (currentSchedule + 1) % VTX_PARAM_COUNT;
+        } while (!vtxUpdatePending && currentSchedule != startingSchedule);
+
         if (!ARMING_FLAG(ARMED) || vtxUpdatePending) {
             vtxCommonProcess(vtxDevice, currentTimeUs);
         }