nvidia-prime with Hybrid/Optimus - does not allow resizing via xrandr

[Joel Wirāmu Pauling (aenertia)]

When using the Nvidia proprietary option - xrandr reports the valid list of modes but is unable to set them via CLI or other methods.

However in Unity using the system-settings->display size the screen is able to be changed.

This is a problem for test suites and applications which rely on xrandr to resize windows.

Phronix Test suite of the system observed can be found here :

http://openbenchmarking.org/result/1605246-KH-1605245KH95

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: nvidia-prime 0.8.2
ProcVersionSignature: Ubuntu 4.4.0-23.41-generic 4.4.10
Uname: Linux 4.4.0-23-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: Unity
Date: Mon May 23 20:46:24 2016
InstallationDate: Installed on 2016-05-23 (0 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: nvidia-prime
UpgradeStatus: No upgrade log present (probably fresh install)

[Joel Wirāmu Pauling (aenertia) (aenertia)]

Some further details documenting the behaviour. Seems modes require setting an --output device explicitly, adding modes to the eDP manually fails (appears only hdmi output can have pre-enumerated modes addded).

This poses several problems in that the --output is not deterministically checked

---
aenertia@huripoki:~$ glxinfo
name of display: :0
display: :0 screen: 0
direct rendering: Yes
server glx vendor string: NVIDIA Corporation
server glx version string: 1.4
server glx extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context,
    GLX_ARB_create_context_profile, GLX_ARB_create_context_robustness,
    GLX_ARB_fbconfig_float, GLX_ARB_multisample, GLX_EXT_buffer_age,
    GLX_EXT_create_context_es2_profile, GLX_EXT_create_context_es_profile,
    GLX_EXT_framebuffer_sRGB, GLX_EXT_libglvnd, GLX_EXT_stereo_tree,
    GLX_EXT_swap_control, GLX_EXT_swap_control_tear,
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_NV_copy_image, GLX_NV_delay_before_swap, GLX_NV_float_buffer,
    GLX_NV_multisample_coverage, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
    GLX_SGI_swap_control, GLX_SGI_video_sync
client glx vendor string: NVIDIA Corporation
client glx version string: 1.4
client glx extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context,
    GLX_ARB_create_context_profile, GLX_ARB_create_context_robustness,
    GLX_ARB_fbconfig_float, GLX_ARB_get_proc_address, GLX_ARB_multisample,
    GLX_EXT_buffer_age, GLX_EXT_create_context_es2_profile,
    GLX_EXT_create_context_es_profile, GLX_EXT_fbconfig_packed_float,
    GLX_EXT_framebuffer_sRGB, GLX_EXT_import_context, GLX_EXT_stereo_tree,
    GLX_EXT_swap_control, GLX_EXT_swap_control_tear,
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_NV_copy_buffer, GLX_NV_copy_image, GLX_NV_delay_before_swap,
    GLX_NV_float_buffer, GLX_NV_multisample_coverage, GLX_NV_present_video,
    GLX_NV_swap_group, GLX_NV_video_capture, GLX_NV_video_out,
    GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, GLX_SGI_swap_control,
    GLX_SGI_video_sync
GLX version: 1.4
GLX extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context,
    GLX_ARB_create_context_profile, GLX_ARB_create_context_robustness,
    GLX_ARB_fbconfig_float, GLX_ARB_get_proc_address, GLX_ARB_multisample,
    GLX_EXT_buffer_age, GLX_EXT_create_context_es2_profile,
    GLX_EXT_create_context_es_profile, GLX_EXT_framebuffer_sRGB,
    GLX_EXT_stereo_tree, GLX_EXT_swap_control, GLX_EXT_swap_control_tear,
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_NV_copy_image, GLX_NV_delay_before_swap, GLX_NV_float_buffer,
    GLX_NV_multisample_coverage, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
    GLX_SGI_swap_control, GLX_SGI_video_sync
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce 920M/PCIe/SSE2
OpenGL core profile version string: 4.5.0 NVIDIA 367.18
OpenGL core profile shading language version string: 4.50 NVIDIA
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
    GL_AMD_multi_draw_indirect, GL_AMD_seamless_cubemap_p...