# X display black after resume from suspend

## equaeghe

Often after I resume from suspend-to-ram, X session display becomes black (after very briefly showing my desktop). Only the mouse pointer is shown (and can be moved). This is something that appeared after a recent X upgrade (or kernel upgrade?). Normally, what happened is that briefly my desktop was shown and then the unlock screen. So now sometimes instead of the unlog screen the diplay turns black.

I have a Thinkpad x220 with internal SB intel GPU and have had many issues that became alleviated by upgrading to the latest kernel releases (I'm now at 4.7.5). My impression is that the screen thinks for some reason that the system is going to sleep and that it needs to turn off. (Pointer still being there? I guess it's a ‘hardware’ cursor outside of the direct control of X.)

For one thing I'm looking for ways to work around this issue. Is there a specific command/program that can turn the screen on/off. (I still have console access, so it really must be an X-related issue, or perhaps the window manager, which is KWin.)

Of course, if others have encountered this issue or a similar one and know a solution or relevant bug report, I'd be very interested in hearing about it.

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## Zucca

Hi.

I have a similar problem, but instead of black I get "color noise". But it's gone when I just switch the virtual desktop. I'm on i3 window manager btw.

I just haven't done anything to solve the problem as it's not that severe. Although some kind of screen refresh might solve my problem.

But you could try to switch to another desktop when this happens. First just see what key combination switches the desks.

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## equaeghe

 *Zucca wrote:*   

> But you could try to switch to another desktop when this happens. First just see what key combination switches the desks.

 

That's a good idea. However, when I tried switching desktops, or more precisely create one, my computer hangs. So I guess I'd first need to investigate that  :Sad: , which is probably related to the intel driver (what else can hang te whole system?).

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## Zucca

 *equaeghe wrote:*   

> However, when I tried switching desktops, or more precisely create one, my computer hangs.

 Hmmm... What method/software you use to suspend? If you happen to use systemd to initiate suspend I have set my desktop PC to use following methods confugured in file /etc/systemd/sleep.conf.

The advantage with systemd-sleep is that it tries different methods (listed in sleep.conf) until it succeeds or runs out of methods.

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## equaeghe

 *Zucca wrote:*   

>  *equaeghe wrote:*   However, when I tried switching desktops, or more precisely create one, my computer hangs. Hmmm... What method/software you use to suspend? If you happen to use systemd to initiate suspend I have set my desktop PC to use following methods confugured in file /etc/systemd/sleep.conf.
> 
> The advantage with systemd-sleep is that it tries different methods (listed in sleep.conf) until it succeeds or runs out of methods.

 

Thanks for the further pointers. I haven't had time to further investigate. However, I discovered that I can switch to a console (Ctrl-Alt-F2) and there do 

```
loginctl unlock-desktops
```

 to get at my desktop on Ctrl-Alt-F1. However, I seem to be able to do this only once, i.e., if I suspend again and the screen is black, then either nothing happens when I try to unlock the desktop this way, or the system hangs hard (manual shutdown using the machine's button is required).

So, my guess is that something crashes the desktop manager (SDDM) and my feeling is, it is the intel driver. When I have time, I'll investigate further.

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