Stupid NVIDIA 3D vgaarb.c patch

[Bruno Prémont]

On Mon, 22 September 2014 Linus Torvalds <torvalds at linux-foundation.org> wrote:
> Adding proper people and mailing lists..
> 
> The PCI_CLASS_DISPLAY_VGA test goes back to the very beginning by
> BenH, and I have no idea if adding PCI_CLASS_DISPLAY_3D is
> appropriate, but hopefully somebody does. The fact that it makes
> things work certainly argues fairly convincingly for it, but I want
> some backup here.
> 
> Dave, BenH?
> 
> Christopher(?), can you please also specify which laptop etc. And the
> patch itself seems to have come from somebody else, unless you're
> Lekensteyn. So we'd want to get the provenance of that too.

More a question to Christopher, but what criteria is preventing the use
of the NVIDIA GPU under this condition?

As far as I've seen on my (single-GPU) systems X requires the GPU to
have boot_vga=1 sysfs attribute to accept autoconfiguration (though
with two GPUs and optimus/switcheroo interaction between the GPUs may
change the picture).

I've been looking at the open, nouveau side of things only. If NVIDIA
closed driver has some other requirement, I don't know.

But as here the intention seems to be to use exclusively the NVIDIA GPU
just leaving the IGD along it should require explicit X configuration
which then does not care about boot_vga.


A more detailed description of what prevents operation with GPU not
being added to vgaarb would certainly help understanding what happens,
what is expected and where things differ.

Bruno

>                 Linus
> 
> On Mon, Sep 22, 2014 at 1:28 PM, C Bergström <cbergstrom at pathscale.com> wrote:
> > Hi Linus,
> >
> > I don't know who the original author is and I can have one of the distro
> > graphics friends review it, but I need this patch below to get NVIDIA
> > drivers to work (without using any Intel graphics) on my laptop
> > http://pastebin.com/wpmFi38k
> >
> > Sorry - I know this is not the proper way to submit a patch, but it's
> > trivial and I'm not a kernel dev.
> >
> > Thanks
> >
> > ./C