[SRU][N/P/Q:unstable][PATCH 0/3] Ubuntu 24.04+ arm64: screen resolution fixed to 1024x768 with last kernel update (LP: #2115068)

[Massimiliano Pellizzer]

BugLink: https://bugs.launchpad.net/bugs/2115068

[ Impact ]

Replace FB_HYPERV with DRM_HYPERV

hyperv_fb is a legacy framebuffer driver that lacks support for dynamic
resolution changes and modern graphics stacks.
hyperv_drm, on the other hand, provides full DRM/KMS integration, enabling
proper display management and compatibility with modern graphics stacks.
Disabling hyperv_fb ensures that hyperv_drm binds to the Hyper-V synthetic video
device, avoiding conflicts and regressions in graphical environments.

[ Fix ]

Enable CONFIG_DRM_HYPERV and disable CONFIG_FB_HYPERV.

[ Test Plan ]

Start a Gen2 Ubuntu VM on Hyper-V.
Verify that it is possible to change the resolution of the screen successfully.

[ Regression Potential ]

Disabling hyperv_fb and relying solely on hyperv_drm may introduce regressions
in environments where DRM/KMS is unavailable. Such environments are increasingly
uncommon, as most modern environments fully support hyperv_drm.

[ Other Info ]

The transition from FB_HYPERV to DRM_HYPERV already happened in Debian 5.17.