Bug 365799

could you please provide the output of: qdbus org.kde.KWin /KWin supportInformation

when the rendering is wrong and after restarting KWin. Please also provide the output of xrandr.

Created attachment 100146 [details]
kwin system log

Does the problem also happen if you use OpenGL 2 in Compositing settings?

(In reply to Martin Gräßlin from comment #3)
> Does the problem also happen if you use OpenGL 2 in Compositing settings?

Yes, tried it now once more since i could not remember, it even kept the laptop screen frozen after unplugging once.

1: Plug in screen -> laptop screen freezes, while the plugged in screen works 
2: (kwin_x11 --replace)
3: now works
4: unplugg new screen
5: screen repaints, however visual flickering/corruption occurs
6: (kwin_x11 --replace
7: now works

Same for opengl 2.0, however in kwin console i see:
OpenGL version: 3.0 instead of 3.3 when running replace when using 2.0 compositor settings instead of 3.1.

Created attachment 100155 [details]
Xrandr when running only laptop

Created attachment 100156 [details]
xrandr with external screen

Created attachment 100157 [details]
kwin when screen corruption occur after unplugging external screen

(In reply to Artur O. from comment #7)
> Created attachment 100157 [details]
> kwin when screen corruption occur after unplugging external screen

most of these errors show up even after --replace and no visual errors occur. Only new in this one is;
QXcbConnection: XCB error: 3 (BadWindow), sequence: 10168, resource id: 35651862, major code: 15 (QueryTree), minor code: 0

But not sure if this is even related or just coincidence.

Here is a link to the video corruption I'm talking about
https://www.youtube.com/watch?v=x8fBxuncT9k

The corruption looks very much like a driver bug, you see the buffer tiles which partially contain junk.
Could be a buffer_age issue - check glxinfo for general support and in case
KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace &

https://community.kde.org/KWin/Environment_Variables#KWIN_USE_BUFFER_AGE

On
> laptop screen stops updating while the second monitor works fine

Can you please dump the supportInformation again, but this time after attaching the screen and when one screen is dead (given that kwin actually responds in this state)
Also, does restarting the compositor (SHIFT+Alt+F12, twice) resolve the state as well?

---
nb: this is on Qt 5.7.0 ...

also give a try to use the (default) OpenGL 2 compositor. OpenGL 3 can create problems with Intel GPUs.

(In reply to Thomas Lübking from comment #10)
> The corruption looks very much like a driver bug, you see the buffer tiles
> which partially contain junk.
> Could be a buffer_age issue - check glxinfo for general support and in case
> KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace &
> 
> https://community.kde.org/KWin/Environment_Variables#KWIN_USE_BUFFER_AGE
> 
> On
> > laptop screen stops updating while the second monitor works fine
> 
> Can you please dump the supportInformation again, but this time after
> attaching the screen and when one screen is dead (given that kwin actually
> responds in this state)
> Also, does restarting the compositor (SHIFT+Alt+F12, twice) resolve the
> state as well?
> 
> ---
> nb: this is on Qt 5.7.0 ...

Well I  played with this at work today. 

* You can drag/move windows when its "frozen", mouse updates as usual when draging occurs just it won't update the screen/window position other than the mouse.

* When toggling compositing with with the combination the moment you turn compositing off the screen updates quickly as nothing has happend. The freeze will also only occur when compositing is enabled. Turning compositing off with the combination and then plugging in the external monitor just works.

* I tried the 'KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace &' but the corruption still occurs.

Created attachment 100182 [details]
glxinfo for ref

It supports bugger age it seems, but wanted to just include whole glxinfo just for ref.

Created attachment 100183 [details]
kwin system log

The systemlog as requested (after the freezing occurs), but not sure if needed now that this seems to be a compositing issue?

I wanted to see KWin's opinion on the screen config ;-)

==> Did you try OpenGL 2.0?

Ftr, GLX_EXT_buffer_age is *not* supported (the listing in client extensions is insufficient, one would expect it in server and general extensions as well)

(In reply to Thomas Lübking from comment #15)
> I wanted to see KWin's opinion on the screen config ;-)
> 
> ==> Did you try OpenGL 2.0?
> 
> Ftr, GLX_EXT_buffer_age is *not* supported (the listing in client extensions
> is insufficient, one would expect it in server and general extensions as
> well)

Well after playing around and searching i found some help in #archlinux channel. Uninstalling xf86-video-intel drivers solved my issues. No more corruption and no more freezing when connecting/disconnecting monitor.

ok, we put it on the list of broken things with Intel xorg driver.