大约两个月以来，我每天都使用笔记本电脑（Acer Nitro 5，AMD Ryzen）和附加屏幕（通过 HDMI 连接），运行良好。现在，内置显示器完全不工作（即使在启动时也不工作），只有辅助显示器可以工作（我看不到登录屏幕）。在显示设置中，我可以看到内置显示器也只有 640x480 的分辨率可用。
相关的 inxi 输出：
System:
Kernel: 5.4.0-137-generic x86_64 bits: 64 compiler: gcc
v: 9.4.0 Desktop: Gnome 3.36.9 info: plank wm: gnome-shell dm: GDM3 3.36.3
Distro: Ubuntu 20.04.5 LTS (Focal Fossa)
Machine:
Type: Laptop System: Acer product: Nitro AN515-43 v: V1.05
Mobo: PK model: Octavia_PKS v: V1.05
UEFI: Insyde v: 1.05 date: 08/07/2019
CPU:
Topology: Quad Core model: AMD Ryzen 5 3550H with Radeon Vega Mobile Gfx
bits: 64 type: MT MCP arch: Zen+ rev: 1 L2 cache: 2048 KiB
flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
bogomips: 33537
Speed: 1224 MHz min/max: 1400/2100 MHz boost: enabled Core speeds (MHz):
1: 1230 2: 1223 3: 1296 4: 1228 5: 1225 6: 1227 7: 1278 8: 1395
Graphics:
Device-1: AMD Baffin [Radeon RX 460/560D / Pro
450/455/460/555/555X/560/560X]
vendor: Acer Incorporated ALI driver: amdgpu v: kernel bus ID: 01:00.0
chip ID: 1002:67ef
Device-2: AMD Picasso vendor: Acer Incorporated ALI driver: amdgpu
v: kernel bus ID: 05:00.0 chip ID: 1002:15d8
Display: x11 server: X.Org 1.20.13 driver: amdgpu compositor: gnome-shell
resolution: 1920x1080~60Hz, 640x480~60Hz
OpenGL: renderer: AMD Radeon Vega 8 Graphics (RAVEN DRM 3.35.0
5.4.0-137-generic LLVM 12.0.0)
v: 4.6 Mesa 21.2.6 direct render: Yes
相关 xrandr 输出：
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
HDMI-A-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 476mm x 268mm
1920x1080 60.00*+ 50.00 59.94
1680x1050 59.88
1280x1024 75.02 60.02
1440x900 59.90
1280x960 60.00
1280x800 60.00
1280x720 60.00 50.00 59.94
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
720x576 50.00
720x480 60.00 59.94
640x480 75.00 72.81 66.67 60.00 59.94
720x400 70.08
eDP connected 640x480+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
640x480 59.94*