Monitor won't sleep

Arch has some of the best docs in the world. Some light reading when you have insomnia:

Scrolling down, we see xset commands and their descriptions:

Command Description xset s off Disable screen saver blanking xset s 3600 3600 Change blank time to 1 hour xset -dpms Turn off DPMS xset s off -dpms Disable DPMS and prevent screen from blanking xset dpms force off Turn off screen immediately xset dpms force standby Standby screen xset dpms force suspend Suspend screen

But you probably need to run

xset q

to see your current settings. Thanks for the question, since I saw the section on how to modify settings for a given tty, as some of my servers don't blank the screen. I've been just hitting the power switch.

Using xset q I get:

eyboard Control: auto repeat: on key click percent: 0 LED mask: 00000000 XKB indicators: 00: Caps Lock: off 01: Num Lock: off 02: Scroll Lock: off 03: Compose: off 04: Kana: off 05: Sleep: off 06: Suspend: off 07: Mute: off 08: Misc: off 09: Mail: off 10: Charging: off 11: Shift Lock: off 12: Group 2: off 13: Mouse Keys: off auto repeat delay: 500 repeat rate: 30 auto repeating keys: 00ffffffdffffbbf fadfffefffedffff 9fffffffffffffff fff7ffffffffffff bell percent: 50 bell pitch: 400 bell duration: 100 Pointer Control: acceleration: 20/10 threshold: 10 Screen Saver: prefer blanking: yes allow exposures: yes timeout: 600 cycle: 600 Colors: default colormap: 0x20 BlackPixel: 0x0 WhitePixel: 0xffffff Font Path: /usr/share/fonts/X11/100dpi/:unscaled,/usr/share/fonts/X11/100dpi,built-ins DPMS (Energy Star): Standby: 600 Suspend: 600 Off: 600 DPMS is Enabled Monitor is On

I don't see anything obviously amiss: it looks like energy saving behavior is on, though it's a little odd to have standby, suspend and off with the same timing. Could the three states somehow conflict with one another? With the "experimental GL " driver the screen turns off as desired. Alas, the machine locks up without worning.

There seem to be two broad classes of monitors, CEA and DMT. I've been letting Raspbian sniff out its own settings. Might forcibly setting the display mode make a difference?

Thanks very much for your reply!

bob prohaska

On this laptop, which is running Fedora 31 Linux and uses the XFCE desktop, so may not do things in quite the same way, as Raspbian.

For instance xset doesn't always do what it says on the tin. For instance, I tried using xset to turn 'Bell' ( ox07, Ctrl-G ) on, off and to change the loudness, frequency and length of the sound. None worked.

XFCE has a Power Manager tool on its Settings menu which does things like controlling what happens when the screen is closed (switch off display, suspend or hibernate)

Similarly, XFCE has delegated screen timeout and blanking timeouts to the Screensaver tool, also on the Settings menu, as well as telling it what timewasting display to show, if any, when it has timed out. This tool also controls what the system does after the screen blanks but is left open without the machine being used - whether it goes to standby, suspend or power off after a long (configurable) period of inactivity.

A number of other Linux desktops delegate control and configuration screen blanking and power saving settings to the screensaver and so, IIRC, does Windows, so its fairly likely that the default Raspbian desktop does the same.

Disclaimer: I don't know for sure that this is the case because my RPi has always been run headless over an SSH session. I've never run it any other way.