glxinfo (used by volt-gui) doesn't seem to detect nvidia prime setups without using nvidia specific environment variables

[AmerXz]

I tried volt-gui release 1.4.1 and when I tried to use my nvidia gpu I couldn't find it in render selector under (OpenGL Rendering Device) it only appeared under (Vulkan Rendering device) so I could only use the nvidia gpu for vulkan games

and that was because glxinfo cannot detect my gpu without these environment variables made from nvidia

__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia

you can find more about nvidia hybrid env vars here

so when I tried MESA_VK_DEVICE_SELECT=list vulkaninfo (which is used in volt-gui) it gave me

MESA_VK_DEVICE_SELECT=list vulkaninfo
MESA-INTEL: warning: Haswell Vulkan support is incomplete
selectable devices:
  GPU 0: 10de:11e2 "NVIDIA GeForce GTX 765M" discrete GPU 0000:01:00.0
  GPU 1: 8086:416 "Intel(R) HD Graphics 4600 (HSW GT2)" integrated GPU 0000:00:02.0
  GPU 2: 10005:0 "llvmpipe (LLVM 22.1.2, 256 bits)" CPU 0000:00:00.

but when I tried glxinfo (also used in volt-gui for OpenGL) it gave me

glxinfo | grep 'OpenGL renderer string'
OpenGL renderer string: Mesa Intel(R) HD Graphics 4600 (HSW GT2)

But when adding nvidia prime env vars before glxinfo command it gave me

__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia glxinfo | grep 'OpenGL renderer string'
OpenGL renderer string: NVIDIA GeForce GTX 765M/PCIe/SSE2

so it seems that nvidia needs those environment variables to be used with opengl apps

anyway thanks for your work

[pythonlover02]

@AmerXz could you check if the current main fixes it? or this build

[AmerXz]

when trying the build you gave me it detected the nvidia gpu but when doing volt glxgears it gave me

volt glxgears
X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  166 (NV-GLX)
  Minor opcode of failed request:  6 ()
  Value in failed request:  0x0
  Serial number of failed request:  32
  Current serial number in output stream:  32

note : I'm using nvidia 470 legacy driver

[pythonlover02]

when trying the build you gave me it detected the nvidia gpu but when doing volt glxgears it gave me

volt glxgears
X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  166 (NV-GLX)
  Minor opcode of failed request:  6 ()
  Value in failed request:  0x0
  Serial number of failed request:  32
  Current serial number in output stream:  32

note : I'm using nvidia 470 legacy driver

Strange because it should be just doing what the NVIDIA page stated, setting this 2 env vars:

__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia

Could you check if this returns the same error:

__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia glxgears

Additionally check:

__GLX_VENDOR_LIBRARY_NAME=nvidia glxinfo | grep 'OpenGL renderer string'

__GLX_VENDOR_LIBRARY_NAME=nvidia glxgears

This last 2 its to check if __NV_PRIME_RENDER_OFFLOAD its really needed, as while i had an NVIDIA GPU i never had to use that env var; and to additionally discard that it was an error on other part of the code.

[AmerXz]

❯ __NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia glxgears

Worked

❯__GLX_VENDOR_LIBRARY_NAME=nvidia glxinfo | grep 'OpenGL renderer string'

this crashed with the output:

❯ __GLX_VENDOR_LIBRARY_NAME=nvidia glxinfo | grep 'OpenGL renderer string'

X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  166 (NV-GLX)
  Minor opcode of failed request:  6 ()
  Value in failed request:  0x0
  Serial number of failed request:  96
  Current serial number in output stream:  96

❯ __GLX_VENDOR_LIBRARY_NAME=nvidia __NV_PRIME_RENDER_OFFLOAD=1 glxinfo | grep 'OpenGL renderer string'

had this output

❯ __GLX_VENDOR_LIBRARY_NAME=nvidia __NV_PRIME_RENDER_OFFLOAD=1 glxinfo | grep 'OpenGL renderer string'
OpenGL renderer string: NVIDIA GeForce GTX 765M/PCIe/SSE2

[pythonlover02]

@AmerXz Question. On the opengl render selector what value do you have set? it works by index (number) like 1=first gpu detected, 2=...., etc.

[AmerXz]

on the build you gave me (from Google drive)

"OpenGL Rendering Device" gave me

1=mesa intel, 2=nvidia geforce gtx 765m, 3=llvmpipe (software rendering), 4=zink

I selected option 2

[pythonlover02]

on the build you gave me (from Google drive)

"OpenGL Rendering Device" gave me

1=mesa intel, 2=nvidia geforce gtx 765m, 3=llvmpipe (software rendering), 4=zink

I selected option 2

Could you paste the volt script content here and try removing some of the os.environ.pop() calls from it and try? The render selector unsets all render related env vars before applying the ones for the selected device, to avoid conflicts with whatever the system already has set but it might be unsetting something that NVIDIA actually needs to function correctly or maybe __NV_PRIME_RENDER_OFFLOAD doesn't gets set on the first place (might have a bug somewhere on the env var collector thats why i ask for the content of the generated script).

[AmerXz]

os.environ.pop('__NV_PRIME_RENDER_OFFLOAD', None)
os.environ.pop('__EGL_VENDOR_LIBRARY_FILENAMES', None)
os.environ.pop('__EGL_VENDOR_LIBRARY_DIRS', None)
os.environ.pop('__EGL_EXTERNAL_PLATFORM_CONFIG_DIRS', None)
os.environ.pop('EGL_DRIVER', None)
os.environ.pop('EGL_PLATFORM', None)
os.environ.pop('EGL_SOFTWARE', None)
os.environ.pop('EGL_DRIVERS_PATH', None)
os.environ.pop('dri_driver', None)
os.environ.pop('DRI_PRIME', None)
os.environ.pop('DRI_PRIME_DEBUG', None)
os.environ.pop('LIBGL_DRIVERS_PATH', None)
os.environ.pop('force_direct_glx_context', None)
os.environ.pop('__NV_PRIME_RENDER_OFFLOAD_PROVIDER', None)
os.environ.pop('DISABLE_LAYER_NV_OPTIMUS_1', None)
os.environ.pop('NVIDIA_VISIBLE_DEVICES', None)
os.environ.pop('DISABLE_LAYER_AMD_SWITCHABLE_GRAPHICS_1', None)
os.environ.pop('device_id', None)
os.environ.pop('NODEVICE_SELECT', None)
os.environ.pop('MESA_VK_DEVICE_SELECT_FORCE_DEFAULT_DEVICE', None)
os.environ.pop('MESA_VK_DEVICE_SELECT_DEBUG', None)
os.environ.pop('VK_ICD_FILENAMES', None)
os.environ.pop('VK_DRIVER_FILES', None)
os.environ.pop('VK_ADD_DRIVER_FILES', None)
os.environ.pop('VK_DRIVERS_PATH', None)
os.environ.pop('VK_DEVSIM_FILENAME', None)
os.environ.pop('__VK_LAYER_NV_optimus', None)




os.environ['__GLX_VENDOR_LIBRARY_NAME'] = 'nvidia'
os.environ['MESA_VK_DEVICE_SELECT'] = '0x10de:0x11e2!'
os.environ['PROTON_DXVK_SAREK'] = '1'
os.environ['PROTON_USE_NTSYNC'] = '1'

prefix = ['gamemoderun']
os.execvp(prefix[0], prefix + sys.argv[1:])