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Kmail bug Netrunner 19.01 Desktop Debian


#1

I am using a HP notebook with built in NVidia Geforce GT 130M video card. KMail crashes with nouveau driver when HTML-view in KMail is activated. Is the only solution to install the NVidia driver 340.xx from the repo or is there another work-around?

KMail is the only issue with the current nouveau-driver on my system.

Thank you.


#2

This is an issue with nouveau playing together with Qt acceleration.
If you don’t want to install the proprietary Nvidia driver you can start kmail with

LIBGL_ALWAYS_SOFTWARE=1 QT_XCB_FORCE_SOFTWARE_OPENGL=1 kmail

If you want to use it more often you can create a new file .config/plasma-workspace/env/nouveau_fix.sh and export the variables like so:

export LIBGL_ALWAYS_SOFTWARE=1
export QT_XCB_FORCE_SOFTWARE_OPENGL=1

Hope that helps :slight_smile:


#3

Thank you for your help. Do you recommend to use the proprietary Nvidia driver on notebooks for a better power consumption (akku) ,performance etc. instead of nouveau driver?


#4

I made the experience to have more issues and higher power usage with the proprietary Nvidia driver. If its a laptop I doubt you will be playing much high end games with it or need the extra power the proprietary driver will provide you.


#5

Okay, thank you. Is it possible to automate the parameters for KMail only? One question to the above mentioned script: will this script executing automatically or how is it to start for making this variables persistent?


#6

Yes every *.sh file that is marked as executable should be automatically run on start of the KDE Plasma desktop. So just adding the script mark it executable should be enough for every login of your user to set the variables.


#7

I have never done it before( no script know-how): how I make it executable?
How I do it only for KMail, because with other programs there are no issues or should I use it generally for all programs?

Please explain it to me in details.


#8

I have never done it before( no script know-how): how I make it executable?

You can make any file executable via the filemanagers properties dialog.
So right click the file go to properties. In the newly opened window click the second tab called Permissions
There you should see a checkbox which you can check to mark this file as executable.

As this is a general issue with Qt nouveau and OpenGL I would suggest to activate this globally.
Other applications that use QtWebEngine like Konqueror, Akregator, Falkon are definitely also affected.

However if you don’t want to activate it globally you could create a new “link to application” on the desktop via using the right click new menu entry and entering the whole command in the program tab executable line:

LIBGL_ALWAYS_SOFTWARE=1 QT_XCB_FORCE_SOFTWARE_OPENGL=1 kmail

Don’t forget to set the Name like KMail and icon on the first tab of this dialog.

If you confirmed that this desktop link is working you can move the file to your home directories .local/share/application directory. The .local directory is a hidden one like every file starting with a dot at the beginning. To make it visible use the toolbars show hidden files button or press ALT+.

Hope that is all understandable :slight_smile:


#9

Thank yo so much, now I understand it fully and I will do it soon. Your support is great.


#10

When i understood it right then the above mentioned environment variables enable software rendering, will the performance of the whole system comes down?


#11

It shouldn’t. Qt in newer versions even disables it by default for the nouveau driver.


#12

A last question to nouveau-driver against NVidia driver: how is the performance of nouveau for video encoding/decoding for looking videos and editing videos etc…?

Thank you.


#13

Nouveau should support the VAAPI video decoding via GPU. So it shouldn’t be a problem. Even video encoding is possible when you use the right tool (ffmpeg for example has vaapi support).
Performance should be better on Nvidia in general when it comes to encoding Videos. For the decoding stuff there isn’t much of a difference I could tell on my testing machines (all relatively low powered older Nvidia chips in Laptops)


#14

Thank you it works well, but the performance of the whole system is going down a little bit (moving a window shows a light jerking).


#15

Are you sure it isn’t just Kmail indexing your mails. Or Akonadi in that case and eating a bit of CPU load?


#16

A last question: the above mentioned noveau_fix script is only valid for some special programs (like KMail etc.) and not for all others, is it right?


#17

It affects all applications that use QtWebEngine.