m/sdlamp2
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix power button shutdown by consolidating input handling in screen monitor

Browse Source 
Both the evtest-based power monitor and the Python screen monitor were
reading /dev/input/event0 simultaneously, causing missed events on the
device's Linux 4.9 kernel. Moved long-press shutdown into the screen
monitor (which already reads event0 directly) and removed the evtest
dependency entirely.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Michael Smith 2026-02-13 21:47:48 +01:00
parent 2142ed7629
commit 3fcae8ea5e
3 changed files with 64 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
docs/sdlamp2-fsd.md
View File

@ -43,6 +43,12 @@ This document specifies the functional requirements for an SDL2 based media play
## 6. Changelog
### 2026-02-13 — Fix power button shutdown regression
- **Consolidated input handling**: Power button long-press shutdown is now handled by `rg35xx-screen-monitor.py` instead of a separate `evtest`-based monitor in the wrapper. Both monitors were reading `/dev/input/event0` simultaneously, causing the `evtest` parser to miss power button events on the device's Linux 4.9 kernel.
- **Timer-based long press**: The screen monitor uses a dynamic `select()` timeout to detect the 3-second hold threshold while the button is still held, rather than waiting for release. On long press, it touches `/tmp/.sdlamp2_shutdown` and sends SIGTERM to sdlamp2.
- **Removed evtest dependency**: The `monitor_power_button()` function and `evtest` pipe are removed from `rg35xx-wrapper.sh`. The screen monitor accepts the sdlamp2 PID as a command-line argument and launches after sdlamp2.
### 2026-02-13 — Screen idle timeout and power button toggle
- **Screen idle timeout**: New Python screen monitor (`rg35xx-screen-monitor.py`) turns off the display after 15 seconds of no input on any device. Audio continues playing. Any button press wakes the screen.

59
tools/rg35xx-screen-monitor.py
View File

@ -1,23 +1,27 @@
#!/usr/bin/env python3
"""
Screen idle timeout and power button toggle for RG35XX Plus.
Screen idle timeout, power button toggle, and long-press shutdown for RG35XX Plus.
Monitors /dev/input/event{0,1,2} for activity. Turns off the screen
(via Allwinner /dev/disp SET_BRIGHTNESS ioctl) after 15s of no input.
Any button press wakes the screen. A short power button press (<2s)
toggles the screen on/off.
toggles the screen on/off. A long press (3s+) triggers clean shutdown.
Launched by rg35xx-wrapper.sh alongside sdlamp2. Killed on cleanup.
Usage: rg35xx-screen-monitor.py <sdlamp2_pid>
"""
import fcntl
import os
import select
import signal
import struct
import sys
import time
IDLE_TIMEOUT = 15 # seconds
POWER_HOLD_THRESHOLD = 2.0 # seconds — short press if released before this
POWER_SHORT_THRESHOLD = 2.0 # seconds — short press if released before this
POWER_LONG_THRESHOLD = 3.0 # seconds — shutdown if held this long
# Allwinner /dev/disp ioctl commands
DISP_GET_BRIGHTNESS = 0x103
@ -50,6 +54,12 @@ def set_brightness(disp_fd, value):
def main():
if len(sys.argv) < 2:
print("Usage: rg35xx-screen-monitor.py <sdlamp2_pid>", file=sys.stderr)
sys.exit(1)
sdlamp2_pid = int(sys.argv[1])
disp_fd = os.open("/dev/disp", os.O_RDWR)
original_brightness = get_brightness(disp_fd)
if original_brightness == 0:
@ -82,14 +92,29 @@ def main():
os.close(disp_fd)
sys.exit(1)
import select
while True:
readable, _, _ = select.select(event_fds, [], [], IDLE_TIMEOUT)
# Dynamic timeout: if power button is held, shorten timeout to detect 3s mark
timeout = IDLE_TIMEOUT
if power_press_time is not None:
remaining = POWER_LONG_THRESHOLD - (time.monotonic() - power_press_time)
if remaining <= 0:
# Already past threshold — trigger shutdown now
touch_and_shutdown(disp_fd, original_brightness, screen_on, sdlamp2_pid)
return
timeout = min(timeout, remaining)
readable, _, _ = select.select(event_fds, [], [], timeout)
# Check long-press threshold (whether select returned due to timeout or input)
if power_press_time is not None:
held = time.monotonic() - power_press_time
if held >= POWER_LONG_THRESHOLD:
touch_and_shutdown(disp_fd, original_brightness, screen_on, sdlamp2_pid)
return
if not readable:
# Timeout — no input for IDLE_TIMEOUT seconds
if screen_on:
# Timeout with no input — turn off screen if idle
if screen_on and power_press_time is None:
set_brightness(disp_fd, 0)
screen_on = False
continue
@ -118,7 +143,7 @@ def main():
elif ev_value == 0 and power_press_time is not None: # release
hold_duration = time.monotonic() - power_press_time
power_press_time = None
if hold_duration < POWER_HOLD_THRESHOLD:
if hold_duration < POWER_SHORT_THRESHOLD:
# Short press — toggle screen
if screen_on:
set_brightness(disp_fd, 0)
@ -126,6 +151,7 @@ def main():
else:
set_brightness(disp_fd, original_brightness)
screen_on = True
# Between SHORT and LONG threshold: ignore (release before 3s)
continue
# Any other key press — wake screen if off
@ -134,5 +160,20 @@ def main():
screen_on = True
def touch_and_shutdown(disp_fd, original_brightness, screen_on, sdlamp2_pid):
"""Signal sdlamp2 to exit and flag for shutdown."""
if not screen_on:
set_brightness(disp_fd, original_brightness)
os.close(disp_fd)
try:
open("/tmp/.sdlamp2_shutdown", "w").close()
except OSError:
pass
try:
os.kill(sdlamp2_pid, signal.SIGTERM)
except OSError:
pass
if __name__ == "__main__":
main()

46
tools/rg35xx-wrapper.sh
View File

@ -4,10 +4,9 @@
#
# Launched by dmenu_ln instead of sdlamp2 directly. Handles device-specific
# concerns that don't belong in the player binary:
# 1. Monitor power button and trigger clean shutdown
# 1. Screen idle timeout, power button screen toggle, and long-press shutdown
# 2. Display the stock firmware's shutdown screen (goodbye.png → /dev/fb0)
# 3. Screen idle timeout (off after 15s) and power button screen toggle
# 4. Launch sdlamp2 as the main process
# 3. Launch sdlamp2 as the main process
#
# Install: copy to /mnt/vendor/bin/rg35xx-wrapper.sh
# Config: set CMD in dmenu_ln to point here instead of sdlamp2 directly
@ -21,53 +20,24 @@ SCREEN_MONITOR="/mnt/vendor/bin/rg35xx-screen-monitor.py"
# works fine even when sdlamp2 replaces the stock menu. Hotspot/AP mode isn't
# needed — SSH access works over the shared network.
# --- Power button monitor ---
# axp2202-pek on /dev/input/event0 sends KEY_POWER (code 116).
# logind has HandlePowerKey=ignore, so we handle it here.
POWER_EVENT_DEV="/dev/input/event0"
monitor_power_button() {
POWER_TIMER_PID=""
evtest "$POWER_EVENT_DEV" 2>/dev/null | while read -r line; do
case "$line" in
*"code 116"*"value 1"*)
# Power button pressed — start 3-second hold timer
( trap 'exit 0' TERM; sleep 3; touch /tmp/.sdlamp2_shutdown; kill -TERM "$SDLAMP2_PID" 2>/dev/null ) &
POWER_TIMER_PID=$!
;;
*"code 116"*"value 0"*)
# Power button released — cancel timer if still running
if [ -n "$POWER_TIMER_PID" ]; then
kill "$POWER_TIMER_PID" 2>/dev/null
wait "$POWER_TIMER_PID" 2>/dev/null
POWER_TIMER_PID=""
fi
;;
esac
done
}
# --- Screen idle timeout + power button screen toggle ---
python3 "$SCREEN_MONITOR" &
SCREEN_MONITOR_PID=$!
# --- Launch sdlamp2 ---
# Run in background so we can capture PID for the power button monitor.
"$SDLAMP2" "$AUDIO_DIR" &
SDLAMP2_PID=$!
monitor_power_button &
MONITOR_PID=$!
# --- Screen monitor (idle timeout + power button toggle + long-press shutdown) ---
# Must launch after sdlamp2 so PID is available. Reads /dev/input/event0
# directly for power button events — no evtest dependency.
python3 "$SCREEN_MONITOR" "$SDLAMP2_PID" &
SCREEN_MONITOR_PID=$!
# Wait for sdlamp2 to finish (signal or normal exit).
wait "$SDLAMP2_PID"
SDLAMP2_EXIT=$?
# --- Cleanup ---
# Kill the screen monitor (SIGTERM restores brightness) and power button monitor.
# Kill the screen monitor (SIGTERM restores brightness).
kill "$SCREEN_MONITOR_PID" 2>/dev/null
wait "$SCREEN_MONITOR_PID" 2>/dev/null
kill "$MONITOR_PID" 2>/dev/null
# If this was a shutdown, call poweroff and block so the loadapp.sh restart
# loop doesn't relaunch dmenu_ln (which would take over the framebuffer and