joystickwake

A joystick-aware screen waker

Manual section:	1
Date:	2023-02-01

Synopsis

joystickwake -h|--help|--version

joystickwake [--command cmd] [--cooldown seconds] [--loglevel level]

Description

Linux gamers often find themselves unexpectedly staring at a blank screen, because their display server fails to recognize game controllers as input devices, allowing the screen blanker to activate during gameplay. This program works around the problem by suppressing screen blankers while joystick activity is detected.

Overview

When installed from a package, joystickwake launches automatically when a user logs in to any modern linux desktop environment. It can also be run manually, without formal installation, since the executable is self-contained.

While running, it monitors udev to find devices with the ID_INPUT_JOYSTICK property (including devices that are plugged in later) and reacts to activity from any of them.

The screen is kept awake by periodically running a heartbeat-like wake command: an external tool provided by the system. Most desktop environments and screen savers include such a command, and joystickwake knows how to use the common ones, so there is normally no need for a user to install or configure one. This design keeps joystickwake compatible with just about every screensaver and power management system there is.

Operation

When joystick activity is detected, all known wake commands are executed. Any command reporting an error or missing from the system will be skipped thereafter. This process repeats in a loop, with a cooldown period between wakes. Joystickwake thereby learns which commands are available on the host system, avoids excessive work that might cause game lag, and minimizes log clutter. In practice, it is very lightweight.

If the python3 dbus-next package is installed, joystickwake will also try to inhibit the desktop environment's screen idle state for a short while after detecting activity, using the org.freedesktop.ScreenSaver interface. This helps with certain environments whose heartbeat-style wake interfaces are missing or broken.

If all known wakers fail, joystickwake will quit. This could happen if no screen blanker is running, or if one that is running requires a custom wake command (see below).

If the python3 Xlib package is installed, joystickwake will quit when the desktop session ends. Otherwise, it will quit when its parent process exits. (This avoids leaving old instances running after the user logs out.)

Log messages are written to standard error, which is normally captured by the desktop environment in a file such as $HOME/.xsession-errors. At the default log level, few messages will be produced, if any.

Configuration and Options

In many desktop environments, no configuration is needed. Joystickwake comes preconfigured with commands that will suppress common screensavers and DPMS power-off. Those commands are:

xset dpms force on
xset s reset
xscreensaver-command -deactivate
gnome-screensaver-command --deactivate
mate-screensaver-command --poke
xfce4-screensaver-command --poke
dbus-send [...] org.freedesktop.ScreenSaver.SimulateUserActivity
dbus-send [...] org.freedesktop.ScreenSaver.Inhibit
dbus-send [...] org.gnome.ScreenSaver.SetActive false

If needed, an additional wake command can be configured in either of the following files:

$XDG_CONFIG_HOME/joystickwake/joystickwake.conf
$HOME/.config/joystickwake/joystickwake.conf

This example illustrates the configuration file format and settings:

command = xdg-screensaver reset # This might work on some desktops
cooldown = 30                   # Number of seconds between wakes
loglevel = warning              # Also: debug, info, error, critical

Command line options --command, --cooldown, and --loglevel will override their corresponding config file settings.

Troubleshooting

The first step in diagnosing a problem is to set joystickwake's log level to debug, restart it, and look for unexpected messages when the problem occurs. Running it in a terminal window may help with log visibility.

Note: Joystickwake cannot see your screen, and therefore has no way to be certain of its state. A success message in the log means only that a wake command ran without reporting an error. That is a good sign, but not always sufficient to wake the screen, especially if that wake command was designed for a screen blanker other than the one in use.

Every log message begins with "joystickwake" and a timestamp, so if you see text in some other format, it comes from another program. For example, one of the wake commands might print a message about being unable to find its screen saver, or your shell's command-not-found script might offer suggestions when joystickwake probes for a command that is not installed on your system. Both of these examples are harmless, and should appear only a few times, since joystickwake avoids failing commands after a few tries.

If joystickwake keeps the screen awake even when all joysticks are idle, it is likely due to "stick drift", meaning that a joystick either is not centering itself properly or is suffering from a faulty sensor. This is unfortunately common in modern game controllers. Other than replacing the hardware or disconnecting it when not in use, this can be resolved by calibrating the dead zones used by the linux evdev and joystick APIs, as described here:

https://wiki.archlinux.org/title/Gamepad#Setting_up_deadzones_and_calibration

If the screen wakes with joystick input, but never blanks again even after all joysticks are disconnected, it could be due to a mismatch between the GNOME screen blanker and one of the wake commands detected on your system. For example, a modern GNOME Shell might misinterpret D-Bus messages intended for the legacy GNOME Screensaver. Possible solutions include installing the python3 dbus-next package (which joystickwake can use to avoid the problem), or switching from GNOME's Wayland session to X11.

If the log shows at least one waker succeeding but the screen still blanks while a joystick is in use, your screen blanker's timeout might be too short for joystickwake. Increasing that timeout or decreasing joystickwake's cooldown setting might help.

Alternatively, it is possible that multiple screen blankers are running, such as a graphical screen saver and a power manager, with joystickwake only knowing how to wake one of them. The solution is to find a command that will wake the problematic one, make sure that command is installed, and if joystickwake doesn't recognize it by default, configure it as a custom command.

If all wakers fail and the screen still blanks, the solution is the same as above: Identify your desktop's screen blanker, install a command that will wake it, and (if necessary) configure joystickwake to use it.

Custom Wake Commands

If none of joystickwake's preconfigured commands wake the screen in a particular desktop environment, finding one that does can require some effort. Asking community members who use the same environment might yield a helpful answer. Once you know the name of the component that blanks the screen, consult its documentation to see if it has a command line tool for controlling it. It may also be worthwhile to query your linux distribution's package manger to see if such a tool was installed along with the screen blanker.

After identifying a command that might work, the next step is to test it, preferably without joystickwake running. The simplest way is to set your screen blanker to use a short timeout (e.g. one minute), run the command preceded by a sleep delay longer than the blanker's timeout, and let your system sit idle to see if it works.

For example, this command line does it with a 77 second delay:

sleep 77; my-cmd --wake

If the screen blanks as expected and then wakes after the sleep delay, the command will probably work with joystickwake. You can try it in a terminal window, like so:

joystickwake --loglevel debug --cooldown 2 --command "my-cmd --wake"

If joystickwake logs a "custom waker failed" message, it means the custom command either produced an error or could not be executed. If pressing a joystick button wakes the screen and logs a "custom waker succeeded" message, then the command works, and can be saved in the configuration file for future login sessions.

When run in a terminal window, Control+C will tell joystickwake to quit.

The xdg-screensaver tool might work as a custom wake command in some environments:

xdg-screensaver reset

Users of KDE Plasma with XWayland might find that joystickwake's preconfigured commands do not suppress the screen energy saving feature. This appears to be a bug in KDE's SimulateUserActivity implementation, reported as bug #440882. A KDE maintainer stated in that report that XWayland is not supported, so the bug seems unlikely to be fixed, but the following custom wake command might be an effective workaround:

qdbus org.kde.Solid.PowerManagement /org/kde/Solid/PowerManagement wakeup

KayJay7/joystickwake