Change nouveau to vesa

Hi All,

First post so lets introduce myself. I am a beginner in cnc that is building a 3-axis machine.With my current PC it 'runs' but not fast, and the PC is quite slow. Almost stuck when the machine is on. I have linux experience (servers, not desktops). Recently someone donated a new PC for my project (3.4 GHZ i7 32GB nvidea 210gt) and the first latency test is promising. Long time below 2000 (ns) with a occasional spike around 12 000. The old pc had a latency around 40 000. only after i disabled nouveau. Before that it was around 300 000. I know 12 000 is still a good figure, but I want it stable. In my experience the vesa driver will get me there.

I am a little bit stuck. A lot has written about it but not quite the situation I am in. This OS version uses Xorg without a config file. When I try to generate one with Xorg -configure this is what I got: "Number of created screens does not match number of detected devices. Configuration failed."

I've tried to disable nouveau in the modprobe.d but no luck there. How do I get Xorg to generate me a good config that I can modify?


Thanks in advance,

Nick

After some testing I found out that the current driver is vesa. Adding only nouveau in the xorg.conf gives me a black screen with a blinking cursor.

The strage thing is that my max resolution with vesa is 800x600. How do I get a better resolution?

Thanks but I've tried that already. Add that while booting (Editing GRUB) but no success. Strange things are happening

- First of all i wanted vesa, now iv'e got it I don't want it :-D. A resolution of 800x600 is to small
- Second: Bigger resolutions gives a blurry unreadable screen. Cant get it sharp and sometimes only 800*600 is available. Quite strange

So in a desperate attempt I added jessie backports to my sources.list to upgrade some of the drivers. A total screwup and dependency hell is what happened. So I tried installing Ubuntu. The setup gave me a flickering colorful screen but no setup.

I am starting to think that the hardware is to 'new' for the distro versions LinuxCNC is based on. To bad Jessie is not supported for machine control. So now I am trying to get my hands on a 8800GT to replace the GT218, Or would ATI make it a better system?

Ive changed the GT218 for a AMD FirePro v7900 on a displayport. Automatic resolution detection is great, its all there! But a new problem has occurred. When I start glxgears I dont see them. I get a black screen. Whats wrong?

[EDIT]
Alright: bbs.archlinux.org/viewtopic.php?id=109132 fixed my Gears :-)

Now the tuning starts. The latency is all over the place. from < 1000 to 25 000.

[EDIT2]

Alright. i've:

1 - added GRUB_CMDLINE_LINUX_DEFAULT="lapic quiet rootdelay=5 radeon.modeset=0 isolcpus=1 acpi_irq_nobalance noirqbalance pci=nomsi" to /etc/default/grub
2 - Removed my ~/.drirc (which i created to get the gears working in the first place)

Not sure what happened (which setting had effect on what) but the results are nice.
- Latency stays below 4500, even with 5x GLX Gears and browsing with iceweasel, etc.
- The selectable resolution went from 2540x1400 to 1280x1024. Looking back at the xorg log I see that radeon was deteting resolutions at first. But now i see vesa is detecting resolutions.
- GLX Gears is working without the .drirc file. So one of the settings in the kernel parameters is fixing it. (I think its the radeon,modeset=0)