Go Back   nV News Forums > Linux Support Forums > NVIDIA Linux

Newegg Daily Deals

Reply
 
Thread Tools
Old 04-25-10, 12:03 AM   #1
rockob
Registered User
 
Join Date: Nov 2008
Posts: 95
Default No refresh using compiz/VNC and X 1.7

If you use VNC to connect to a PC running X server 1.7 (eg I'm running 2:1.7.6-2ubuntu7), compiz and nvidia restricted drivers (including the latest 195.36.24 drivers), the VNC screen stays static (there is no refresh), although the host PC screen refreshes correctly. Running VNC with the -noxdamage argument is a workaround (but this is very slow).

A fuller description is at https://bugs.launchpad.net/bugs/353126:

When using the nvidia-restricted or some ATI drivers and compiz desktop effects the vnc server will not refresh the screen. This is being caused by the xserver not getting "damaged" by the nvidia-restricted drivers. Linked bugs confirm this is not an issue on intel chipsets or nv driver.

Steps to reproduce:
Enable desktop-effects (default) with nvidia-restricted, virtualBox's display or some ATI driver like RV610
Enable remote desktop
Connect with VNC

Results:
You see a screen snapshot of your desktop but if you click a menu item there are no updates to the screen.
Notes:
If you close and restart the vnc session, you get an updated snapshot but still no refreshes.

Workarounds:
Use the -noxdamage argument with vncviewer. This is really inefficient and bandwidth hungry since the whole screen refreshes.
Kill compiz and use a different wm (metacity).
Attached Files
File Type: gz nvidia-bug-report.log.gz (48.1 KB, 98 views)
rockob is offline   Reply With Quote
Old 04-25-10, 04:32 AM   #2
Dragoran
Registered User
 
Join Date: May 2004
Posts: 711
Default Re: No refresh using compiz/VNC and X 1.7

This is not a driver bug ...
Dragoran is offline   Reply With Quote
Old 04-25-10, 06:23 AM   #3
gradinaruvasile
Registered User
 
gradinaruvasile's Avatar
 
Join Date: May 2008
Posts: 199
Default Re: No refresh using compiz/VNC and X 1.7

1. Compiz is buggy.
2.Compiz+vnc is not a good combination.

Just disable compiz on the target machine. I gave up on compiz since i installed Xubuntu 9.10 (and now in Debian) and since then my desktops are way more stable.

Also the nv driver doesnt support compiz at all. And this issue is present on all compiz running machines i ever seen (ati with OSS drivers, nvidia with proprietary).
gradinaruvasile is offline   Reply With Quote
Old 04-25-10, 07:04 AM   #4
smani
Registered User
 
Join Date: Apr 2010
Posts: 2
Default Re: No refresh using compiz/VNC and X 1.7

Quote:
Originally Posted by gradinaruvasile View Post
And this issue is present on all compiz running machines i ever seen (ati with OSS drivers, nvidia with proprietary).
That is not true, with XServer 1.7 as in Fedora 12 and Ubuntu 10.04, it works fine on all open drivers.
smani is offline   Reply With Quote
Old 04-25-10, 08:47 AM   #5
gradinaruvasile
Registered User
 
gradinaruvasile's Avatar
 
Join Date: May 2008
Posts: 199
Default Re: No refresh using compiz/VNC and X 1.7

I said i ever seen. I have seen Ubuntu 7.10-9.10.

And compiz is buggy and it is a poor choice of enabling it by default.
gradinaruvasile is offline   Reply With Quote
Old 04-25-10, 11:10 AM   #6
smani
Registered User
 
Join Date: Apr 2010
Posts: 2
Default Re: No refresh using compiz/VNC and X 1.7

Quote:
Originally Posted by gradinaruvasile View Post
And compiz is buggy and it is a poor choice of enabling it by default.
This may indeed be true, but won't calm down most of the people in launchpad experiencing this issue. It would be interesting though to get a statement from a nvidia driver developer whether
1. This issue was not known
2. This issue is known and on the TODO list
3. This issue is known but won't be addressed for some reason

As stated on the launchpad post, the issue does not appear to be with compiz directly since it worked back in 2008. One possibility might be a change at xserver level which was not taken into consideration by the nvidia binary driver (among other) - for this reason an "official" statement would be nice.
smani is offline   Reply With Quote
Old 04-25-10, 02:18 PM   #7
gradinaruvasile
Registered User
 
gradinaruvasile's Avatar
 
Join Date: May 2008
Posts: 199
Default Re: No refresh using compiz/VNC and X 1.7

It might work back in 8.04/8.10 for some users (didnt work for me though).
What VNC client did you use? Try out Remmina, it is better than the default vinagre.
May be an xorg/nvidia/compiz issue/regression though. Take in account the fact that compiz too is at newer version.
gradinaruvasile is offline   Reply With Quote
Old 04-26-10, 10:35 AM   #8
AaronP
NVIDIA Corporation
 
AaronP's Avatar
 
Join Date: Mar 2005
Posts: 2,487
Default Re: No refresh using compiz/VNC and X 1.7

There were some limitations in the X server that prevented x11vnc from working correctly with Compiz, but I added some code to the X server in the 1.7 timeframe to allow the driver to fix that particular problem. It should be working, but it sounds like something is going wrong with that handshaking. I'll try to take a look soon.
AaronP is offline   Reply With Quote

Old 04-26-10, 08:18 PM   #9
AaronP
NVIDIA Corporation
 
AaronP's Avatar
 
Join Date: Mar 2005
Posts: 2,487
Default Re: No refresh using compiz/VNC and X 1.7

I looked into this today and found that the NVIDIA driver does not correctly generate damage events for a given window when the OpenGL rendering is actually happening to a child window. In this case, x11vnc is listening for damage events on the root, but Compiz is rendering to the Composite Overlay Window, which counts as a child window as far as this code is concerned. I'll try to fix the window hierarchy problem for a future release.

In the meantime, you can work around the problem by using Compiz's --use-root-window option, or by modifying Compiz to call XCreateDamage(dpy, cow, XDamageReportNonEmpty) to trigger damage events on the root window when it renders to the COW.
AaronP is offline   Reply With Quote
Old 04-28-10, 07:21 AM   #10
mobrien
Registered User
 
Join Date: Sep 2004
Posts: 5
Default Re: No refresh using compiz/VNC and X 1.7

Wow, this is great information!

It looks like Compiz is run as simply "compiz" (from a binary in /usr/bin/) in Ubuntu (10.04 at least). Does anyone have any idea where Compiz is started/called from, so I can simply change it?

I don't want to just create a shell script redirecting to compiz with this switch, because it may be overwritten by an update. (of course, so could changing a script that starts it on login, I guess)

Also, I would imagine it would be helpful to post here where Compiz is started in other distros, if anyone knows.

Thanks AaronP! This looks like, at least, a great temporary solution!

--mobrien118
mobrien is offline   Reply With Quote
Old 04-28-10, 10:38 AM   #11
Dragoran
Registered User
 
Join Date: May 2004
Posts: 711
Default Re: No refresh using compiz/VNC and X 1.7

Quote:
Originally Posted by AaronP View Post
[...]
In the meantime, you can work around the problem by using Compiz's --use-root-window option
Note that this requires enabling the DisableGLXRootClipping in xorg.conf (device or screen section).
Dragoran is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:29 AM.


Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 1998 - 2014, nV News.