Bug#731265:

[Vincent Cheng]

Hi Beren,

On Sun, Aug 31, 2014 at 8:05 AM, Beren Minor <beren.minor at gmail.com> wrote:
> Dear Maintainer,
>
> I had the same problem on a Debian Sid, with Nvidia drivers version 340.32,
> ie: xrandr reporting "cap: 0x0" and being unable to set the source output
> provider.
>
> I have found that the issue came from the drm feature that was not enabled
> during the dkms build of the driver. It looks like that with previous
> versions of the driver, the compilation of the drm support was conditionally
> enabled in conftest_nvidia.sh, but with 340.32, it looks like the
> configuration tests have been converted to a simple conftest.h using kbuild
> feature test macros.
>
> In this new conftest.h, the drm feature is not tested anymore, and is
> disabled by a #if 0.

Hmmm, I'm a bit flummoxed about why NV_DRM_AVAILABLE is being
unconditionally disabled; I can't find anything in d/changelog about
this (other than saying this new conftest.sh function was added in
319.17-1), and Andreas doesn't seem to be around nowadays to answer
any questions I might have.

I'd point out that this drm feature being disabled has been around for
a long time, e.g. it's been there since wheezy [1] and perhaps
earlier? So it doesn't look like it only affects 340.32, and it should
affect earlier versions?

Could you please attach a debdiff with your changes? All that you had
to change to fix this was debian/module/conftest.h, right?

Regards,
Vincent

[1] http://sources.debian.net/src/nvidia-graphics-drivers/304.117-1/debian/module/conftest.h/