Single window randomly freezes (no input possible)
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| gdm3 (Ubuntu) |
New
|
Undecided
|
Unassigned | ||
Bug Description
Ubuntu version:
Description: Zorin OS 12.1 (Ubuntu 16.04 LTS)
Release: 12
Package:
gdm3:
Installed: 3.18.3-0ubuntu2
Candidate: 3.18.3-0ubuntu2
Version table:
*** 3.18.3-0ubuntu2 500
500 http://
100 /var/lib/
Description:
This bug makes lets a window freeze, however the application inside it does not freeze. It is not possible to focus the window anymore, nor to resize it. The cursor does not change the icon to the resize icon and the window doesn't respond to clicks or hovering events. However, the application itself is fine - for example, Firefox will continue to play music. Alt+F4 to exit the application still works. It has happened to me in Thunar, Sublime Text and Firefox and the Gnome Shell, so I don't think the bug has to do with the application. The title bar buttons may still work on the frozen window (see below).
The window can be made responsible again by opening a second window and having it partially, not completely (!) overlap the frozen window or by resizing the window (does however not work with Super+Right shortcuts for tiling, you have to move the mouse and click the "restore maximized window" button). The bug often occurs after restoring a window to the maximized state after it has been pushed into the background for a prolonged time (as far as I can tell).
For example, if I put Firefox into the background to play music, leave it in maximized state, open a text editor maximized so that Firefox is completely hidden, come back 20 minutes later and bring Firefox in the foreground, Firefox is almost (not always) guaranteed to be frozen, but the music still plays.
It is possible that two windows freeze at the same time, for example, I had two instances of Thunar (file manager) in the background, both frozen and the title bar buttons didn't work either.
The bug occurs in several stages (not sure if two bugs or the same). About one hour after logging in (as far as I can tell), some windows (noticably the ones in the background, meaning not visible or completely hidden behind another window) become unresponsive. Sometimes the title bar still works, at which point you can unfreeze the window by clicking the "restore" button in the title bar. In this stage, the window is only unresponsive to clicks and mouse focus events.
Sometimes, this isn't possible either because the application has no window decoration or because the title bar is not responding, too. In this stage the window will not respond to a cursor hovering over the edge of the window. The cursor won't change. Then you have to open another application window and have it partially overlap the frozen window. The frozen window will immediately become responsive again.
After stage 2 has happened about 5 times, the cursor will start to click about 100 pixels to the left. This has happened twice in different applications, not sure if really related and a bug or just a "quirk" (?). The cursor will show and the application is responsive, but the recorded click will be around 100 pixels to the left. An application restart fixes this problem.
The bug occurs randomly, I sadly can't give an exact estimate for when it happens. It's just that when it starts, it will return in about 10 - 20 minutes after first occurence. I can't say if this happens on other distributions or if this is a known bug. Zorin OS 12 is Ubuntu 16.04 with a themed GNOME window manager.
Hardware information:
H/W path Device Class Description
=======
/0 bus 4236B87
/0/1 processor Intel(R) Core(TM) i5-2520M CPU @ 2.5
/0/1/2 memory 64KiB L1 cache
/0/1/3 memory 256KiB L2 cache
/0/1/4 memory 3MiB L3 cache
/0/5 memory 4GiB System Memory
/0/5/0 memory 4GiB SODIMM DDR3 Synchronous 1333 MH
/0/5/1 memory DIMMProject-
/0/e memory 128KiB BIOS
/0/100 bridge 2nd Generation Core Processor Family
/0/100/2 display 2nd Generation Core Processor Family
/0/100/16 communication 6 Series/C200 Series Chipset Family
/0/100/16.3 communication 6 Series/C200 Series Chipset Family
/0/100/19 enp0s25 network 82579LM Gigabit Network Connection
/0/100/1a bus 6 Series/C200 Series Chipset Family
/0/100/1a/1 usb1 bus EHCI Host Controller
/0/100/1a/1/1 bus Integrated Rate Matching Hub
/0/100/1a/1/1/4 communication Broadcom Bluetooth Device
/0/100/1a/1/1/6 multimedia Integrated Camera
/0/100/1b multimedia 6 Series/C200 Series Chipset Family
/0/100/1c bridge 6 Series/C200 Series Chipset Family
/0/100/1c.1 bridge 6 Series/C200 Series Chipset Family
/0/100/1c.1/0 wlp3s0 network Centrino Ultimate-N 6300
/0/100/1c.3 bridge 6 Series/C200 Series Chipset Family
/0/100/1c.4 bridge 6 Series/C200 Series Chipset Family
/0/100/1c.4/0 generic MMC/SD Host Controller
/0/100/1d bus 6 Series/C200 Series Chipset Family
/0/100/1d/1 usb2 bus EHCI Host Controller
/0/100/1d/1/1 bus Integrated Rate Matching Hub
/0/100/1d/1/1/5 generic Integrated Smart Card Reader
/0/100/1f bridge QM67 Express Chipset Family LPC Cont
/0/100/1f.2 storage 6 Series/C200 Series Chipset Family
/0/100/1f.3 bus 6 Series/C200 Series Chipset Family
/0/100/1f.5 storage 6 Series/C200 Series Chipset Family
/0/0 scsi0 storage
/0/0/0.0.0 /dev/sda disk 160GB ST9160412AS
/0/0/0.0.0/1 /dev/sda1 volume 145GiB EXT4 volume
/0/0/0.0.0/2 /dev/sda2 volume 3982MiB Extended partition
/0/0/0.0.0/2/5 /dev/sda5 volume 3982MiB Linux swap / Solaris partiti
/0/2 scsi1 storage
/0/2/0.0.0 /dev/cdrom disk DVD RW AD-7710H
/1 power 42T4911
Thank you for reading.
