Since upgrading to 4.15 some apps (including the gnome lock screen) have broken
rendering after locking the screen. Other apps affected are google-chrome and
aisleriot. (both might be GL user) also the gnome top bar is sometimes not
rendered correctly.
In the log you can find a lot of messages like this when locking and unlocking
a screen:
```
Feb 05 17:43:07 barghest kernel: nouveau 0000:03:00.0: fb: trapped write at
000003fb10 on channel 2 [1fb8e000 DRM] engine 0d [PCE0] client 13 [] subclient
02 [] reason 00000002 [PAGE_NOT_PRESENT]
Feb 05 17:43:07 barghest kernel: nouveau 0000:03:00.0: ce0: intr 00000200
```
```
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: NVIDIA GT218 (0a8c00b1)
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: bios: version
70.18.83.00.08
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: fb: 512 MiB DDR3
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: VRAM: 512 MiB
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: GART: 1048576 MiB
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: TMDS table version
2.0
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB version 4.0
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB outp 00:
02000360 00000000
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB outp 01:
02000362 00020010
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB outp 02:
028003a6 0f220010
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB outp 03:
01011380 00000000
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB outp 04:
08011382 00020010
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB outp 05:
088113c6 0f220010
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB conn 00:
00101064
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: DCB conn 01:
00202165
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: MM: using COPY for
buffer copies
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: DRM: allocated 1920x1200
fb: 0x70000, bo 00000000a5b52db1
Feb 05 13:35:38 barghest kernel: fbcon: nouveaufb (fb0) is primary device
Feb 05 13:35:38 barghest kernel: nouveau 0000:03:00.0: fb0: nouveaufb frame
buffer device
Feb 05 13:35:38 barghest kernel: [drm] Initialized nouveau 1.3.1 20120801 for
0000:03:00.0 on minor 0
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (==) Matched nouveau
as autoconfigured driver 1
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (==) Matched nouveau
as autoconfigured driver 4
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) LoadModule:
"nouveau"
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) Loading
/usr/lib64/xorg/modules/drivers/nouveau_drv.so
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) Module nouveau:
vendor="X.Org Foundation"
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) [drm] nouveau
interface version: 1.3.1
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) NOUVEAU(0):
[DRI2] DRI driver: nouveau
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) NOUVEAU(0):
[DRI2] VDPAU driver: nouveau
Feb 05 13:35:49 barghest /usr/lib/gdm/gdm-x-session[3165]: (II) AIGLX: Loaded
and initialized nouveau
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (==) Matched nouveau
as autoconfigured driver 1
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (==) Matched nouveau
as autoconfigured driver 4
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) LoadModule:
"nouveau"
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) Loading
/usr/lib64/xorg/modules/drivers/nouveau_drv.so
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) Module nouveau:
vendor="X.Org Foundation"
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) [drm] nouveau
interface version: 1.3.1
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) NOUVEAU(0):
[DRI2] DRI driver: nouveau
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) NOUVEAU(0):
[DRI2] VDPAU driver: nouveau
Feb 05 13:35:59 barghest /usr/lib/gdm/gdm-x-session[3462]: (II) AIGLX: Loaded
and initialized nouveau
```