From 08ab2b6beeb7faf039cf7d46811e06cac5ed8fcc Mon Sep 17 00:00:00 2001
From: enricobuehler <buehler@unom.io>
Date: Tue, 7 Jul 2026 08:07:42 +0200
Subject: [PATCH] =?UTF-8?q?fix(android):=20declare=20WAKE=5FLOCK=20?=
 =?UTF-8?q?=E2=80=94=20the=20stream's=20Wi-Fi=20locks=20never=20actually?=
 =?UTF-8?q?=20engaged?=
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WifiLock.acquire() enforces the WAKE_LOCK permission, which the manifest never
declared — every acquisition since the first Wi-Fi lock shipped threw
SecurityException, silently swallowed by a bare runCatching. The phone's own
accounting proved it (dumpsys wifi: high_perf/low_latency active_time_ms = 0
across weeks of streams): every on-device session ran with Wi-Fi power save
fully active, whatever the code intended. Verified live after the fix: both
locks registered in WifiLockManager, mPowerSaveDisableRequests=2, ping RTT to
the streaming phone 3.8 ms avg. A failed acquire now logs loudly — this class
of failure must never be invisible again.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 clients/android/app/src/main/AndroidManifest.xml    |  6 ++++++
 .../main/kotlin/io/unom/punktfunk/StreamScreen.kt   | 13 ++++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/clients/android/app/src/main/AndroidManifest.xml b/clients/android/app/src/main/AndroidManifest.xml
index 932c3d6c..1bc78c58 100644
--- a/clients/android/app/src/main/AndroidManifest.xml
+++ b/clients/android/app/src/main/AndroidManifest.xml
@@ -13,6 +13,12 @@
          reception needs it (also an OEM Wi-Fi power-save hedge). -->
     <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <!-- WifiLock.acquire() ENFORCES this (a normal permission, granted at install). Without it the
+         stream's Wi-Fi locks throw SecurityException and power save stays on: downlink delivery
+         clumps at beacon intervals — hundreds of ms of latency mush + periodic whole-frame loss.
+         Its absence went unnoticed for weeks because the acquire was wrapped in a silent
+         runCatching (now logged). -->
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
     <!-- Enforced from Android 17 (SDK 37) for ALL local-network traffic incl. the QUIC socket.
          Harmless to declare on earlier releases. -->
     <uses-permission android:name="android.permission.ACCESS_LOCAL_NETWORK" />
diff --git a/clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt b/clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt
index 8dc852f3..fd91c1c8 100644
--- a/clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt
+++ b/clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt
@@ -6,6 +6,7 @@ import android.content.pm.ActivityInfo
 import android.content.pm.PackageManager
 import android.net.wifi.WifiManager
 import android.os.Build
+import android.util.Log
 import android.view.SurfaceHolder
 import android.view.SurfaceView
 import android.view.WindowManager
@@ -126,8 +127,10 @@ fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
     //  - FULL_HIGH_PERF covers older releases — it is deprecated AND a documented no-op on recent
     //    Android, which is exactly why it can't be the only lock (a lesson learned: holding just
     //    HIGH_PERF left power save fully active on Android 13+).
-    // Needs no permission beyond ACCESS_WIFI_STATE (declared). Non-reference-counted: one explicit
-    // acquire/release each.
+    // acquire() ENFORCES the WAKE_LOCK permission (manifest) — and a failed acquire MUST be loud:
+    // a silent runCatching hid the missing permission for weeks (dumpsys wifi showed
+    // low_latency_active_time_ms=0 across every "locked" stream). Non-reference-counted: one
+    // explicit acquire/release each.
     val wifiLocks = remember(handle) {
         val wm = context.applicationContext.getSystemService(Context.WIFI_SERVICE) as? WifiManager
             ?: return@remember emptyList<WifiManager.WifiLock>()
@@ -144,7 +147,11 @@ fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
 
     DisposableEffect(handle) {
         window?.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
-        wifiLocks.forEach { runCatching { it.acquire() } }
+        wifiLocks.forEach { lock ->
+            runCatching { lock.acquire() }.onFailure { e ->
+                Log.w("punktfunk", "WifiLock acquire failed — power save stays ON: $lock", e)
+            }
+        }
         // HDMI Auto Low-Latency Mode: ask the display to drop its post-processing (game mode) —
         // the biggest panel-side latency win on the TV boxes. No-op where ALLM isn't supported. API
         // 30+. Part of the experimental low-latency stack.