Bug#798207: nvidia-legacy-340xx-driver: Wrong module loaded, X fails to start when legacy installed alongside mainline driver

[Andreas Beckmann]

On 2015-09-15 10:44, Luca Boccassi wrote:
> If I remember correctly, to test that I just deleted the legacy uvm module
> and ran depmod again, but it didn't make any difference, I think because
> uvm is not loaded at boot anyway. This is all from memory as I can't check
> right now. Later tonight or tomorrow I'll look again and give more details
> and answer all the other questions. Sorry for the delay!

you should be able to test with
  nvidia-graphics-drivers-legacy-340xx 340.76-6
  nvidia-graphics-drivers 340.93-1

I don't have the opportunity to make tests requiring frequent reboots.
But I did a lot of modprobe tests yesterday and have hopefully
identified the solution. You can find it in 340.93-2 (unreleased) and it
should be easy to manually apply it to the modprobe.conf in the legacy
package.

to test:

modprobe -v nvidia
modprobe -v nvidia-uvm
modprobe -r -v nvidia
modprobe -r -v nvidia-uvm

with different sets of modules loaded before these commands (0, 1, 2)

and with the nvidia alternative set to either current or legacy

Please also test glx-alternatives from SVN. Drop xorg.conf (or any
xorg.conf.d snippet you created) and ensure that the nvidia module is
loaded before X is started - Xorg should automatically find and use
nvidia now :-)

What is needed to make the module loaded at boot?
  echo nvidia > /etc/modules-load.d/nvidia.conf
could be sufficient


Andreas