VLC 2.1.0 failing to inhibit DPMS on XFCE

from what I understand, VLC has two methods to inhibit DPMS, dbus and xdg-screensaver.

for some reason on v2.1.0 it fails to start xdg-screensaver even though it selects that method so when a video is playing VLC is not able to prevent the monitor from entering standby.

on VLC v2.0.8

main debug: looking for inhibit module: 2 candidates
main debug: using inhibit module "xdg_screensaver"
xdg_screensaver debug: started xdg-screensaver (PID = 2036)

[~]# xset -q | grep "DPMS is" "DPMS is Disabled"

on VLC v2.1.0

main debug: looking for inhibit module matching "any": 2 candidates
dbus_screensaver debug: cannot find service org.freedesktop.ScreenSaver
dbus_screensaver debug: cannot find service org.freedesktop.PowerManagement.Inhibit
dbus_screensaver debug: cannot find service org.mate.SessionManager
dbus_screensaver debug: cannot find service org.gnome.SessionManager
main debug: using inhibit module "xdg_screensaver"

no process is spawned, and... [~]# xset -q | grep "DPMS is" "DPMS is Enabled"

Added attachment:

• vlc_2_0_8__debug.txt

Added attachment:

• vlc_2_1_0__debug.txt

further information and reproduction method below

OS: Arch or Manjaro / x86_64 DE/WM: XFCE latest tested in a VM, so hardware info shouldn't matter.

---

steps to reproduce

1. Goto http://manjaro.org/get-manjaro/ .
2. Download XFCE (Main version), boot LiveCD.
3. test VLC v2.0.8 (already installed on livecd) using a random video and in a terminal execute xset -q, DPMS gets triggered properly (on playing / stop).
4. now update vlc (pacman -S VLC), you may need to download a few small updates first.
5. do step 3 again with VLC v2.1.0, DPMS is no longer being switched anymore and the monitor will turn off while a video plays (I suggest you set DPMS to turn off after a short interval like 10 seconds to make testing faster).

VLC no longer prints the PID in the debug. But it would print an error if it failed to start xdg-screensaver. I fail to see any VLC bug in your log.

I guess that "xdg-screensaver reset" does not work on your DE. If you think this is a VLC bug, please attach a strace log (i.e. run "strace -f vlc 2>log" and wait 31 seconds before you quit VLC).

added Component::Interface: other plugins Status::not VLC labels

closed

removed Status::not VLC label

reopened

assigned to @funman

confirmed

here's the strace as requested. https://mega.co.nz/#!QptWELxZ!OUmo2lS-Q1V0z87UmgGyvWfRczoD9mBXCr8A64FFJ50

Mega is not a place to paste straces...

Replying to [comment:2 courmisch]:

VLC no longer prints the PID in the debug. But it would print an error if it failed to start xdg-screensaver. I fail to see any VLC bug in your log.

I guess that "xdg-screensaver reset" does not work on your DE. If you think this is a VLC bug, please attach a strace log (i.e. run "strace -f vlc 2>log" and wait 31 seconds before you quit VLC).

Sorry but Shadowized opened the bug at my request, after we started investigating this bug yesterday.

Please do not close it,

thanks

And it says:

[pid  2089] execve("/usr/bin/xdg-screensaver", ["xdg-screensaver", "reset"], [/* 47 vars */] <unfinished ...>
...
[pid  2089] <... execve resumed> )      = 0

So VLC is executing xdg-screensaver correctly. Not only that, but xdg-screensaver runs and exits just fine:

[pid  2089] exit_group(0)               = ?
[pid  2089] +++ exited with 0 +++

Problem is between xdg-utils and the DE exactly as I already wrote. Not much of a surprise considering that xdg-utils is broken and unmaintained and the main DE's have switched to D-Bus. And I wonder why this bug was reopened before the log was posted.

added Status::not VLC label

closed

Mega does not work on Firefox, so, it's not really a place to use as paste.

ok so my initial report was a little incorrect, xdg-screensaver does spawn but it appears to be using the wrong command to inhibit. my understanding of xdg-screensaver's documentation is "xdg-screensaver reset" simply kills screensavers, but doesn't effect DPMS at all, and I'm not even sure it prevents screensavers from starting in the first place.

The previously used method in VLC v2.0.8 worked fine, but as courmisch said "xdg-utils is broken and unmaintained", that makes me wonder why is VLC even using it then if it doesn't work right. I don't know of any other media players(mplayer, mplayer2, mpv) that use xdg-utils to inhibit DPMS.

this _is_ a VLC defect imo.

in VLC 2.0.8 which worked fine, it uses

execve("/usr/bin/xdg-screensaver", ["xdg-screensaver", "suspend", "0x0280004b"], [/* 47 vars */] <unfinished ...>

and in VLC v2.1.0, it uses

execve("/usr/bin/xdg-screensaver", ["xdg-screensaver", "reset"], [/* 47 vars */]) = 0

removed Status::not VLC label

reopened

Hi courmisch,

Please do not close this bug again until we understand what is going on.

Thank you,

Replying to [comment:12 Shadowized]:

ok so my initial report was a little incorrect, xdg-screensaver does spawn but it appears to be using the wrong command to inhibit. my understanding of xdg-screensaver's documentation is "xdg-screensaver reset" simply kills screensavers, but doesn't effect DPMS at all, and I'm not even sure it prevents screensavers from starting in the first place.

The previously used method in VLC v2.0.8 worked fine, but as courmisch said "xdg-utils is broken and unmaintained", that makes me wonder why is VLC even using it then if it doesn't work right. I don't know of any other media players(mplayer, mplayer2, mpv) that use xdg-utils to inhibit DPMS.

this _is_ a VLC defect imo.

in VLC 2.0.8 which worked fine, it uses {{{ execve("/usr/bin/xdg-screensaver", ["xdg-screensaver", "suspend", "0x0280004b"], [/* 47 vars */] <unfinished ...> }}}

and in VLC v2.1.0, it uses {{{ execve("/usr/bin/xdg-screensaver", ["xdg-screensaver", "reset"], [/* 47 vars */]) = 0 }}}

If you look at xdg-screensaver you will see that it calls

xset dpms force on

repeatedly, so while DPMS stays enabled it should reset the timer.

I tried by changing the timeout with xset s 40 (vlc calls xdg-screensaver every 30 seconds) and the screen doesn't blank for me (gnome shell).

Note you can reset with xset s 0.

However when using dbus inhibitor when the dpms delay is elapsed the screen goes black, the gnome screensaver does not deactivate DPMS or reset the delay either.

IMO we should always deactivate DPMS manually.

xfce interface for power management

Added attachment:

• xfce-c.png

Can you see if that patch disables DPMS and screensaver?

Added attachment:

• 0001-Support-xfce-power-management-interface.patch

Using vlc 2.1.4 on Fedora, xfce 4.10.1 -- screensaver is activated while playing video

I have the same issue - XFCE & Arch linux & VLC 2.1.4. It works fine with 2.0.8a where it correctly disables DPMS. I tried the attached patch but it didn't help - it does not disable DPMS while playing and causes the monitor to enter standby after set timeout.

main debug: looking for inhibit module matching "any": 2 candidates
dbus_screensaver debug: cannot find service org.freedesktop.ScreenSaver
dbus_screensaver debug: cannot find service org.freedesktop.PowerManagement.Inhibit
dbus_screensaver debug: found service org.freedesktop.PowerManagement
main debug: using inhibit module "dbus_screensaver"

If XFCE's implementation of org.freedesktop.PowerManagement, there is little VLC can do.

added Status::not VLC label

closed

Filed ustream bug: https://bugzilla.xfce.org/show_bug.cgi?id=11083