Improper retrieval of EDID information. Kernel regression introduced in 6.7.
Dmesg shows completely different outputs for connected monitor (LVDS_1) depending on which kernel version is used. Kernels 6.6 and below perform as expected. Kernels 6.7 and above retrieve improper EDID information which results in a much larger than native display resolution, while displaying only a portion of the screen.
There is a bug report open on openSUSE's bugzilla.
Relevant dmesg on each kernel: On 6.6.x:
[ 6.177015] [ T381] [drm:drm_client_modeset_probe]
[ 6.177027] [ T381] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:61:LVDS-1]
[ 6.178918] [ T381] nouveau 0000:01:00.0: [drm:update_display_info.part.0] [CONNECTOR:61:LVDS-1] Assigning EDID-1.4 digital sink color depth as 6 bpc.
[ 6.178926] [ T381] nouveau 0000:01:00.0: [drm:update_display_info.part.0] [CONNECTOR:61:LVDS-1] ELD monitor t Flat Panel
[ 6.178930] [ T381] nouveau 0000:01:00.0: [drm:update_display_info.part.0] [CONNECTOR:61:LVDS-1] ELD size 36, SAD count 0
[ 6.178937] [ T381] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:61:LVDS-1] status updated from unknown to connected
[ 6.178949] [ T381] nouveau 0000:01:00.0: [drm:update_display_info.part.0] [CONNECTOR:61:LVDS-1] Assigning EDID-1.4 digital sink color depth as 6 bpc.
[ 6.178954] [ T381] nouveau 0000:01:00.0: [drm:update_display_info.part.0] [CONNECTOR:61:LVDS-1] ELD monitor t Flat Panel
[ 6.178958] [ T381] nouveau 0000:01:00.0: [drm:update_display_info.part.0] [CONNECTOR:61:LVDS-1] ELD size 36, SAD count 0
[ 6.178991] [ T381] nouveau 0000:01:00.0: DRM: native mode from preferred
[ 6.179328] [ T381] [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:61:LVDS-1] probed modes :
[ 6.179338] [ T381] [drm:drm_mode_debug_printmodeline] Modeline "1920x1080": 60 144000 1920 1980 2040 2100 1080 1085 1090 1144 0x48 0xa
[ 6.179353] [ T381] [drm:drm_mode_debug_printmodeline] Modeline "1920x1080": 50 144000 1920 2048 2176 2304 1080 1088 1096 1250 0x40 0xa
...
On 6.10.x:
[ 6.953800] [ T388] nouveau 0000:01:00.0: [drm:drm_client_modeset_probe]
[ 6.953810] [ T388] nouveau 0000:01:00.0: [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:42:LVDS-1]
[ 6.956127] [ T388] nouveau 0000:01:00.0: [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:42:LVDS-1] status updated from unknown to connected
[ 6.956296] [ T388] nouveau 0000:01:00.0: [drm:drm_helper_probe_single_connector_modes] [CONNECTOR:42:LVDS-1] probed modes:
[ 6.956301] [ T388] nouveau 0000:01:00.0: [drm:drm_helper_probe_single_connector_modes] Probed mode: "2048x1536": 60 200000 2048 2096 2112 2144 1536 1553 1554 1555 0x48 0x5
[ 6.956307] [ T388] nouveau 0000:01:00.0: [drm:drm_helper_probe_single_connector_modes] Probed mode: "1920x1200": 60 193476 1920 2056 2256 2592 1200 1203 1209 1245 0x0 0x6
[ 6.956312] [ T388] nouveau 0000:01:00.0: [drm:drm_helper_probe_single_connector_modes] Probed mode: "1920x1080": 60 173106 1920 2048 2248 2576 1080 1083 1088 1120 0x0 0x6
...
Full outputs: dmesg_kernel_6.6.47-1-longerm.txt