Recently upgraded from 20.04 to 21.04, which installed kernel 5.11. Now it fails to start X with correct screen dimensions, due I assume to this in Xorg log:
[ 23.307] (EE) open /dev/dri/card0: No such file or directory
If I boot the 5.4 kernel, everything works properly.
FWIW:
00:02.0 VGA compatible controller: Intel Corporation HD Graphics 630 (rev 04)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108 [GeForce GT 430] (rev a1)
# lshw -C video
*-display
description: VGA compatible controller
product: GF108 [GeForce GT 430]
vendor: NVIDIA Corporation
capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
configuration: driver=nouveau latency=0
*-display
description: VGA compatible controller
product: HD Graphics 630
vendor: Intel Corporation
capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
Further update: compared the dmesg outputs after booting each kernel. The 5.11 one makes no mention of nouveau
, where the 5.4 one is full of it.