Android 14 Google TV: dumpsys … | grep -q writes "Broken pipe" into output → screen_on/awake misparsed, device reported off #373

Title: Android 14 Google TV: dumpsys … | grep -q writes "Broken pipe" into output → screen_on/awake misparsed, device reported off

Device

• Chromecast with Google TV 4K (sabrina), Android 14 (SDK 34)
• Build: google/sabrina_prod_stable/sabrina:14/UTTC.250917.004/14193937:user/release-keys
• Home Assistant 2026.10.1, androidtv integration (direct ADB, port 5555, no ADB server), device class auto

Problem
The media player is reported off (sometimes idle) while the TV is on and playing (Disney+ in foreground, media session PLAYING).

Cause
CMD_SCREEN_ON_AWAKE_WAKE_LOCK_SIZE pipes dumpsys power into grep -q. grep -q exits on the first match, and on this firmware dumpsys then prints an error that ends up in the ADB shell output:

$ (dumpsys power | grep 'Display Power' | grep -q 'state=ON' || dumpsys power | grep -q 'mScreenOn=true' || dumpsys display | grep -q 'mScreenState=ON') && echo -n 1 || echo -n 0; dumpsys power | grep mWakefulness | grep -q Awake && echo -n 1 || echo -n 0; dumpsys power | grep Locks | grep 'size='
1Failed to write while dumping service power: Broken pipe
1Wake Locks: size=2

_screen_on_awake_wake_lock_size() reads output[1] as the awake flag. Here it is F, so awake=False. The device is then treated as off, and get_properties(lazy=True) skips the remaining properties. The message is timing-dependent, so the state flips between off and idle.

Each command on its own returns the correct values (screen on, mWakefulness=Awake, Wake Locks: size=2, media session state=PLAYING(3)).

Suggested fix
Send dumpsys stderr to /dev/null (e.g. dumpsys power 2>/dev/null | grep -q …) in the screen/awake/wake-lock commands, or avoid grep -q early exit (grep … > /dev/null). Either one keeps the error text out of the parsed output.