Bug 350807

Summary: Desktop freezes when monitor switched off
Product: [Plasma] Powerdevil Reporter: Dan Ciarniello <danny>
Component: generalAssignee: Plasma Development Mailing List <plasma-devel>
Status: RESOLVED UPSTREAM    
Severity: normal CC: christoph, kde
Priority: NOR    
Version: 5.3.2   
Target Milestone: ---   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Dan Ciarniello 2015-07-31 04:23:06 UTC
When "Screen Energy Saving" is enabled, the desktop freezes when the monitor is switched off.

The mouse is still active and moving it or hitting a key on the keyboard turns the monitor back on but nothing (task bar, desktop icons, open windows) responds to mouse clicks.  

This is on a system recently (2 days ago) updated from Fedora 21 to Fedora 22.

Reproducible: Always

Steps to Reproduce:
1. Enable "Screen Energy Saving" and apply
2. Wait for monitor to turn off
3. Move mouse to turn monitor back on

Actual Results:  
Desktop is frozen

Expected Results:  
Desktop usable

System: Fedora 22
lspci -v output for graphics controller:
00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller])
        DeviceName: Intel(R) HD Graphics Device
        Subsystem: Intel Corporation Device 2030
        Flags: bus master, fast devsel, latency 0, IRQ 27
        Memory at f7800000 (64-bit, non-prefetchable) [size=4M]
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at f000 [size=64]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
        Capabilities: [d0] Power Management version 2
        Capabilities: [a4] PCI Advanced Features
        Kernel driver in use: i915
        Kernel modules: i915
Comment 1 Kai Uwe Broulik 2015-07-31 07:04:33 UTC
What do you mean by frozen? Is it just the Plasma desktop or everything? Can you try without compositing (Alt+Shift+F12)?
Comment 2 Dan Ciarniello 2015-07-31 14:34:37 UTC
It is just the Plasma desktop; the computer otherwise works.  Disabling compositing (I disabled it through System Settings -> Display and Monitor -> Compositor) doesn't make a difference, the Plasma desktop still freezes.
Comment 3 Dan Ciarniello 2015-08-02 06:45:06 UTC
Apparently, having one of the "monitor" widgets (i. e. CPU Load Monitor, Hard Disk I/O Monitor or Network Monitor) on the desktop will cause this to happen.

I've had the plasma desktop freeze without those but it's sporadic.  Having one of those widgets guarantees it.

Also, on the off chance that the problem is caused by a problem migrating from KDE 4 to 5, I tried with a new user and was still able to reproduce the issue.
Comment 4 Christoph Cullmann 2015-10-05 13:05:31 UTC
Thats a Qt bug:

https://bugreports.qt.io/browse/QTBUG-42985