Hi, I just had to cleanse my last arch+kde install due to a corrupted update.
External screen worked fine before but now it’s not connecting. I’m connecting through usb-c to the port with GPU passthrough. It’s fully black and when I try to change the settings to use it, my laptop screen goes like this. The display is recognized in xrandr with all available resolutions. The display isn’t recognized on launch either. I need to unplug and plug it again (something that wasn’t an issue before either).
inxi -Full
System:
Host: g14 Kernel: 6.9.7-arch1-1 arch: x86_64 bits: 64
Desktop: KDE Plasma v: 6.1.1 Distro: Arch Linux
Machine:
Type: Laptop System: ASUSTeK product: ROG Zephyrus G14 GA401QM_GA401QM
v: 1.0 serial: <superuser required>
Mobo: ASUSTeK model: GA401QM v: 1.0 serial: <superuser required>
uuid: <superuser required> UEFI: American Megatrends LLC. v: GA401QM.412
date: 08/30/2022
Battery:
ID-1: BAT0 charge: 54.8 Wh (100.0%) condition: 54.8/76.0 Wh (72.0%)
volts: 15.8 min: 15.8
CPU:
Info: 8-core model: AMD Ryzen 9 5900HS with Radeon Graphics bits: 64
type: MT MCP cache: L2: 4 MiB
Speed (MHz): avg: 1160 min/max: 400/4680 cores: 1: 400 2: 400 3: 1916
4: 2035 5: 2395 6: 400 7: 400 8: 400 9: 1916 10: 400 11: 1915 12: 400
13: 2394 14: 2395 15: 400 16: 400
Graphics:
Device-1: NVIDIA GA106M [GeForce RTX 3060 Mobile / Max-Q] driver: nvidia
v: 555.58
Device-2: AMD Cezanne [Radeon Vega Series / Radeon Mobile Series]
driver: amdgpu v: kernel
Display: x11 server: X.Org v: 21.1.13 with: Xwayland v: 24.1.0 driver: X:
loaded: modesetting,nvidia dri: radeonsi gpu: amdgpu resolution: 1: N/A
2: 1920x1080~144Hz
API: EGL v: 1.5 drivers: nvidia,radeonsi,swrast
platforms: x11,surfaceless,device
API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: amd mesa v: 24.1.2-arch1.1
renderer: AMD Radeon Graphics (radeonsi renoir LLVM 17.0.6 DRM 3.57
6.9.7-arch1-1)
API: Vulkan v: 1.3.279 drivers: nvidia surfaces: xcb,xlib
Audio:
Device-1: NVIDIA GA106 High Definition Audio driver: snd_hda_intel
Device-2: AMD Renoir Radeon High Definition Audio driver: snd_hda_intel
Device-3: AMD ACP/ACP3X/ACP6x Audio Coprocessor driver: N/A
Device-4: AMD Family 17h/19h HD Audio driver: snd_hda_intel
API: ALSA v: k6.9.7-arch1-1 status: kernel-api
Server-1: PipeWire v: 1.2.0 status: active
Network:
Device-1: MEDIATEK MT7921 802.11ax PCI Express Wireless Network Adapter
driver: mt7921e
IF: wlan0 state: down mac: 42:21:7f:03:c3:d6
Device-2: Realtek USB 10/100/1000 LAN driver: r8152 type: USB
IF: enp4s0f4u2u1 state: up speed: 1000 Mbps duplex: full
mac: 00:e0:4c:68:05:af
Bluetooth:
Device-1: MediaTek Wireless_Device driver: btusb type: USB
Report: rfkill ID: hci0 state: up address: see --recommends
Drives:
Local Storage: total: 476.94 GiB used: 8.52 GiB (1.8%)
ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLQ512HBLU-00B00
size: 476.94 GiB
Partition:
ID-1: / size: 19.52 GiB used: 6.83 GiB (35.0%) fs: ext4 dev: /dev/nvme0n1p2
label: N/A uuid: 80552021-7587-4167-a026-082dfe6b5540
ID-2: /boot size: 1022 MiB used: 55.3 MiB (5.4%) fs: vfat
dev: /dev/nvme0n1p1 label: N/A uuid: 3527-0DE3
ID-3: /home size: 447.71 GiB used: 1.64 GiB (0.4%) fs: ext4
dev: /dev/nvme0n1p3 label: N/A uuid: 1c87a2e9-13b6-4bfa-9fa6-67bad9027ffa
Swap:
ID-1: swap-1 type: zram size: 4 GiB used: 0 KiB (0.0%) dev: /dev/zram0
Sensors:
System Temperatures: cpu: 54.8 C mobo: 38.0 C gpu: amdgpu temp: 47.0 C
Fan Speeds (rpm): cpu: 2800
Info:
Memory: total: 16 GiB note: est. available: 15.03 GiB used: 4.41 GiB (29.3%)
Processes: 335 Uptime: 1h 6m Shell: fish inxi: 3.3.35
I could really use the help here 
Edit: I tried with a usbc - hdmi adapter, same thing happened. In both x11 and Wayland. Tried hdmi directly to the hdmi entry and it connected perfectly. My assumption is that this may be an issue with nvidia? the Usbc port has gpu pass throguh and the hdmi port used the igpu which is amd.
Any suggestions on how to fix this?
So connecting the external display to the HDMI port works well, but connecting it to the USB-C w/ DP, it does not work at all - but it used to work in a previous installation?
You are using the latest Nvidia drivers, so I don’t think its a driver issue.
Can you show the output of kscreen-doctor -o when the screen is connected but inactive?
Output: 66 eDP-1
enabled
connected
priority 1
Panel
Modes: 69:1920x1080@144*! 70:1920x1080@60 71:1920x1080@120 72:1920x1080@96 73:1920x1080@72 74:1920x1080@60 75:1920x1080@50 76:1920x1080@48 77:1920x1080@60 78:1920x1080@60 79:1920x1080@60 80:1920x1080@60 81:1680x1050@144 82:1680x1050@60 83:1680x1050@60 84:1400x1050@75 85:1400x1050@60 86:1600x900@60 87:1600x900@60 88:1600x900@60 89:1600x900@60 90:1280x1024@144 91:1280x1024@85 92:1280x1024@75 93:1280x1024@60 94:1440x900@144 95:1400x900@60 96:1400x900@60 97:1280x960@85 98:1280x960@60 99:1440x810@60 100:1440x810@60 101:1368x768@60 102:1368x768@60 103:1280x800@144 104:1280x800@60 105:1280x800@60 106:1280x800@60 107:1280x800@60 108:1152x864@75 109:1280x720@144 110:1280x720@60 111:1280x720@60 112:1280x720@60 113:1280x720@60 114:1024x768@144 115:1024x768@85 116:1024x768@75 117:1024x768@60 118:1024x768@85 119:1024x768@75 120:1024x768@70 121:1024x768@60 122:1024x768@87 123:960x720@85 124:960x720@75 125:960x720@60 126:928x696@75 127:928x696@60 128:896x672@75 129:896x672@60 130:1024x576@60 131:1024x576@60 132:1024x576@60 133:1024x576@60 134:960x600@60 135:960x600@60 136:832x624@75 137:960x540@60 138:960x540@60 139:960x540@60 140:960x540@60 141:800x600@144 142:800x600@85 143:800x600@75 144:800x600@70 145:800x600@65 146:800x600@60 147:800x600@85 148:800x600@72 149:800x600@75 150:800x600@60 151:800x600@56 152:840x525@60 153:840x525@60 154:864x486@60 155:864x486@60 156:700x525@75 157:700x525@60 158:800x450@60 159:800x450@60 160:640x512@85 161:640x512@75 162:640x512@60 163:700x450@60 164:700x450@60 165:640x480@144 166:640x480@85 167:640x480@60 168:640x480@85 169:640x480@73 170:640x480@75 171:640x480@60 172:720x405@60 173:720x405@59 174:720x400@85 175:684x384@60 176:684x384@60 177:640x400@60 178:640x400@60 179:640x400@85 180:576x432@75 181:640x360@60 182:640x360@60 183:640x360@60 184:640x360@59 185:640x350@85 186:512x384@85 187:512x384@75 188:512x384@70 189:512x384@60 190:512x384@87 191:512x288@60 192:512x288@60 193:416x312@75 194:480x270@60 195:480x270@60 196:400x300@85 197:400x300@72 198:400x300@75 199:400x300@60 200:400x300@56 201:432x243@60 202:432x243@60 203:320x240@85 204:320x240@73 205:320x240@75 206:320x240@60 207:360x202@60 208:360x202@59 209:360x200@85 210:320x200@85 211:320x180@60 212:320x180@59 213:320x175@85
Geometry: 0,0 1920x1080
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Color profile source: incapable
Output: 67 HDMI-1
disabled
disconnected
priority 0
HDMI
Modes:
Geometry: 0,0 0x0
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Color profile source: incapable
Output: 642 DP-1-0
disabled
connected
priority 0
DisplayPort
Modes: 82:1680x1050@60 92:1280x1024@75 119:1024x768@75 120:1024x768@70 121:1024x768@60 148:800x600@72 149:800x600@75 150:800x600@60 151:800x600@56 170:640x480@75 171:640x480@60 644:1920x1080@60 653:720x480@60 1776:3440x1440@60! 1777:3840x2160@60 1778:3840x2160@50 1779:3840x2160@30 1780:3440x1440@144 1781:3440x1440@120 1782:3440x1440@100 1783:3440x1440@85 1784:2560x1440@120 1785:2560x1440@60 1786:2560x1080@120 1787:2560x1080@60 1788:1920x1080@120 1789:1440x900@60 1790:1280x720@60 1791:1280x720@50 1792:1024x768@120 1793:1024x768@100 1794:800x600@120 1795:800x600@100 1796:640x480@120 1797:640x480@100 1798:640x480@73
Geometry: 0,0 3440x1440
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Color profile source: incapable
Output: 654 DP-1-1
disabled
disconnected
priority 0
DisplayPort
Modes:
Geometry: 0,0 0x0
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Color profile source: incapable
I quickly reinstalled arch and KDE, this time with linux-lts kernell and the same issue occurs.
I think i’ll try xfce to see if something changes.
A. On another post here someone mentioned that their GPU and screen are both DP 2.1 but the USB-C DP alt-mode connection only worked once they configured their screen to force DP 1.4, and I speculated that it’s because their USB-C to DP cable wasn’t an active DP 2.1 certified cable. I think that is something to consider in this case as well.
B. Your DP-1-0 connection seems to be detected properly - it has a mode list for a 4K display. I would try to just enable it with the doctor - something like: kscreen-doctor output.642.enable output.642.mode.1920x1080@60 (start with lower resolution mode and see if that may help).
