Bridge link fixes2

adc_issue/saadc_deadlock_repro/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(saadc_deadlock_repro)
+
+target_sources(app PRIVATE src/main.c)

device/src/connections.c

@@ -143,6 +143,7 @@ void Connections_ResetWatermarks(connection_id_t connectionId) {
 
     Connections[connectionId].watermarks.txIdx = 0;
     Connections[connectionId].watermarks.rxIdx = 255;
+    Connections[connectionId].watermarks.rxIdxValid = false;
 }
 
 void Connections_ReportState(connection_id_t connectionId) {

device/src/connections.h

@@ -69,6 +69,7 @@
     typedef struct {
         uint8_t rxIdx;
         uint8_t txIdx;
+        bool rxIdxValid;
     } ATTR_PACKED connection_watermarks_t;
 
     typedef struct {

device/src/keyboard/key_scanner.c

@@ -301,6 +301,8 @@ static void scanAllKeys() {
     }
 
     if (DEVICE_IS_UHK80_LEFT) {
+        // If ack gets lost, second key state change will block (because uart is busy with control of the first one). That blocks us. Third keystate change may be lost.
+        // TODO: consider passing this via postponer queue.
         Messenger_Send2(DeviceId_Uhk80_Right, MessageId_SyncableProperty, SyncablePropertyId_LeftHalfKeyStates, compressedBuffer, compressedLength);
     }
 }