Arch Linux

AcousticBruce

Member

Registered: 2015-03-03

Posts: 64

Confused with graphics driver behavior. nouveau, nvidia-340xx, xfce4

On a brand new system install with no special drivers installed and only a user, I install xfce4. Xfce4 mentions a few dependency, one of which is a nvidia driver. I go ahead and choose "nvidia-340xx". Everything installs wonderfully. XFCE4 loads in extremely fast. Good resolutions, can run games like wesnoth, websites render good and scroll fast, videos plays. Here is the issue. When I lspci, I get this:

Subsystem: Dell Device 040a
Kernel driver in use: nouveau
Kernel modules: nouveau

So I went ahead and reinstalled the nvidia-340xx with pacman and I now get this:

Subsystem: Dell Device 040a
Kernel driver in use: nvidia
Kernel modules: nouveau, nvidia

Before installing the nvidia-340xx drivers, I believe graphics drivers were initialized as the kernel was loading (forgive me if I did not say this right). Now it does not initialized until I go start xfce. Let me explain.

My setup does not automatically load startx or startxfce. It just goes to a shell. BEFORE manually installing the nvidia-340xx drviers it looked and ran WAY better. The text would be smaller and the resolution would look better. Also if I ran a command like lspci -k, the output would QUICKLY render text and it would be so fast you couldnt read everything as it scrolled. Now, the text is big, resolution is lame, when I type something like lspci -k it goes slow, inf fact it is slow enough to were you can skim the output as it is being displayed.

Something fishy is going on here and I would like to understand what is happening. Any ideas?

mrunion

Member

From: Jonesborough, TN

Registered: 2007-01-26

Posts: 1,938

Website

Re: Confused with graphics driver behavior. nouveau, nvidia-340xx, xfce4

Though I'm no expert, I believe this has to do with KMS. nVidia's official drivers don't support this, so you have to pick which you'd rather have -- nVidia binary drivers, or noveau and better text mode handling.

(I may have said all this wrong, so YMMV.)

---

Matt

"It is very difficult to educate the educated."

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: Confused with graphics driver behavior. nouveau, nvidia-340xx, xfce4

Yes, it's KMS. Search the forum for solutions e.g. https://wiki.archlinux.org/index.php/Uvesafb

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: Confused with graphics driver behavior. nouveau, nvidia-340xx, xfce4

Nothing fishy is going on. nouveau handles both the console and X, the nvidia driver handles only X.

And no, contrary to above posts, this is not directly related to KMS. It's about providing a fbdev (framebuffer device) interface on top of which a fbcon (framebuffer console) is running. KMS provides a fbdev interface, the nvidia driver doesn't. There's no technical reason why not, it's just that the nvidia driver is primarily a workstation driver and none of Nvidia's workstation clients care about the console, so Nvidia has no incentive to create a fbdev interface.

Last edited by Gusar (2015-05-27 15:12:45)

AcousticBruce

Member

Registered: 2015-03-03

Posts: 64

Re: Confused with graphics driver behavior. nouveau, nvidia-340xx, xfce4

Would there be any way to load the generic drivers and hold off on the nvidia-340xx drivers until I start up xfce? I am not to familiar with how the kernel operates to load drivers. Just wondering if this is possible?

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: Confused with graphics driver behavior. nouveau, nvidia-340xx, xfce4

Yes, see the link karol provided. vesafb and uvesafb are such generic drivers. Do note that they may not provide your display's native resolution.

If you're thinking loading nouveau for the console and the nvidia driver for X, that's not possible. the two drivers would fight over control of the GPU, that can't possibly work.