Dear Maintainer,

I have an ASUS G550JK, muxless Optimus laptop. All four display outputs are
wired to the Intel iGPU and the GTX 850M has no DRM connectors at all, so the
card is only ever used for render offload.

Rendering on it fails most of the time: the kernel kills the channel and the
client dies with ENODEV. The card itself is fine; the runs that do get through
render correctly and fast, around 2400-2500 FPS on the glmark2 texture scene,
where the iGPU scores 1846 overall. On 7.1.13 roughly one run in three works.

I'm filing this against the kernel rather than Mesa for two reasons. It happens
on 7.0.13, 7.1.8 and 7.1.13 with Mesa unchanged at 26.1.6-1. And it hits Mesa's
GL driver and NVK in the same way, both ending with the channel killed and
ENODEV. Please reassign if you disagree.

Hardware and versions:

  01:00.0 3D controller [0302]: NVIDIA Corporation GM107M [GeForce GTX 850M] [10de:1391] (rev a2)
  00:02.0 VGA compatible controller [0300]: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06)

  Debian forky/sid amd64, GNOME 50 on Wayland
  kernel 7.1.13+deb14-amd64, also tested on 7.1.8+deb14.1 and 7.0.13+deb14
  Mesa 26.1.6-1, libdrm2 2.4.134-3

nouveau issues no firmware request on this chip and none fails; GM107 doesn't
need the signed ACR blobs.

How I test:

  for i in 1 2 3 4 5 6; do
    DRI_PRIME=1 timeout 90 glmark2 --off-screen -b texture:duration=3
    sleep 4
  done