Display blacks out for a few seconds after inactivity

smirky · 2019-09-07 20:28:48

Hello all.

I've been having this problem since more than a year now and due to its behavior and my lack of knowledge in video drivers (not saying they are the cause of my problem, but could be), I'm posting about it in this section.

After a few minutes of inactivity in a graphical environment:
- plasma without lockscreen
- plasma with lockscreen
- just sddm prompt, waiting for credentials
- heck, even non-graphical environment, just TTY

I get a display timeout, which basically disconnects my monitor and after 3-4 seconds, it turns back on.
I don't have any settings on my user for turning off the display after X minutes after inactivity.
Initially, I thought that my DE configs are borked, but obviously it triggers on newly created users too.
Then I started suspecting it could be due to the new (by the time this started, it was pretty much new) changes in AMD's GPU driver, related to the massive pull request for AMDKFD or whatever it was called.
Since this was not really much of a deal, as it was only happening due to inactivity, I didn't really gave it much time for troubleshooting.
However, if I start a kwin_wayland session on Plasma and this issue triggers, the whole screen becomes unusable, but it does have backlight. I can't even switch TTYs.
Eventually, I found I can ssh through another device and kill the DE, which restores my control, but I definitely find it annoying.

Honestly, I'm not sure what's causing this.
I tried changing mesa drivers to mesagit, but as I said, it happens even on a TTY console, where mesa is out of the way.
I tried changing the HDMI ports on the GPU.
I haven't tried a different monitor, but I'm pretty sure I don't need to, as it doesn't appear to be the problem, due to its nature.
No new entries appear in dmesg when it happens.

I'm using Radeon RX480.

Not sure what else is relevant to share in order to get to the bottom of this, but please bare with me, I'm willing to pastebin as much as I can to get this over with.

seth · 2019-09-07 20:55:23

https://wiki.archlinux.org/index.php/Di … _Signaling ?

smirky · 2019-09-07 21:16:20

So as per that wiki page, DPMS is something built-in into the kernel and it's not related to X or wayland in any way.
It can be queried with an X utility, which is awesome:

 $ xset q
Keyboard 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:  150    repeat rate:  25
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  2/1    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  600
Colors:
  default colormap:  0x20    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  /usr/share/fonts/misc,/usr/share/fonts/TTF,/usr/share/fonts/OTF,built-ins
DPMS (Energy Star):
  Standby: 600    Suspend: 600    Off: 600
  DPMS is Enabled
  Monitor is On

However, it doesn't explain 2 things.
Why it started happening all the sudden?
Why is the display turning on 3-4 seconds after it happens without interaction?

Anyway, I've disabled it with `xset -dpms` and now I'm going to wait 10 minutes (estimated it) to see the results.

EDIT:
Now that I found out about DPMS, thanks to you, it does seem very odd looking at these bug reports here:
https://bugs.freedesktop.org/buglist.cg … esolution=---

People complaining about black screen, DPMS issues, etc...

https://bugs.freedesktop.org/show_bug.cgi?id=107928
https://bugs.freedesktop.org/show_bug.cgi?id=106940
https://bugs.freedesktop.org/show_bug.cgi?id=109239 (seems to be pointing to Polaris 10, which is my area)

Last edited by smirky (2019-09-07 21:27:24)

seth · 2019-09-08 06:02:09

Why it started happening all the sudden?

No idea, but dpms defaults to active for X11

Why is the display turning on 3-4 seconds after it happens without interaction?

My best guess is that your desktop environment reacts to the lost output ("basically disconnects my monitor") in a way that breaks DPMS.
Could also be an amdgpu issue (according to your link it's caused by dc)
Interesting module parameters:

modinfo amdgpu | grep -E '(pm|dc):'

smirky · 2019-09-08 17:55:05

 # modinfo amdgpu | grep -E '(pm|dc):'
parm:           dpm:DPM support (1 = enable, 0 = disable, -1 = auto) (int)
parm:           aspm:ASPM support (1 = enable, 0 = disable, -1 = auto) (int)
parm:           runpm:PX runtime pm (1 = force enable, 0 = disable, -1 = PX only default) (int)
parm:           bapm:BAPM support (1 = enable, 0 = disable, -1 = auto) (int)
parm:           dc:Display Core driver (1 = enable, 0 = disable, -1 = auto (default)) (int)

seth · 2019-09-08 17:56:27

Yeah, I know the output of that command…
The idea was to play w/ those parameters (disable them) to see whether it makes a difference.

Arch Linux

#1 2019-09-07 20:28:48

Display blacks out for a few seconds after inactivity

#2 2019-09-07 20:55:23

Re: Display blacks out for a few seconds after inactivity

#3 2019-09-07 21:16:20

Re: Display blacks out for a few seconds after inactivity

#4 2019-09-08 06:02:09

Re: Display blacks out for a few seconds after inactivity

#5 2019-09-08 17:55:05

Re: Display blacks out for a few seconds after inactivity

#6 2019-09-08 17:56:27

Re: Display blacks out for a few seconds after inactivity

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