Found 0 GPUs, cannot create backend

[tigerjack]

Please fill out the following:

• Sway Version:

  • swaymsg -t get_version: sway version 1.7

• Debug Log:
  After running sway as sway -d, this is the output.
  https://pastebin.com/Utd6QzNL

• Configuration File:

• Stack Trace:

• Description:
  Just launching sway from tty sometimes result in sway not launching. The problem appears at random and sometimes a reboot suffices to fix it.

May be related to this old bug.

[emersion]

00:00:00.006 [DEBUG] [wlr] [backend/session/session.c:385] Ignoring '/dev/dri/card0': not a KMS device

Can you post a drm_info log when this happens?

It seems like the kernel driver is half-loaded or something. Maybe look into dmesg as well.

[BridgerB]

I just ran into this same error. I am on arch and have been updating daily so there might have been a package today that did it (2022-11-09). I am now bricked out of my machine. I use the Nvidia open-source nouveau driver. I use this script at login: https://wiki.archlinux.org/title/sway#Automatically_on_TTY_login. I login (login text is also larger than normal), then it loads for ~5 seconds then it flashes the screen below before going back to a fresh login page.

[bl4ckb0ne]

@tigerjack @BridgerB what are your GPUs?

[BridgerB]

I have a single Nvidia 1080. This morning I booted into an adjacent hard drive and removed my auto start sway script. I am now able to login to a TTY but after updating everything sway still has the same error.

[BridgerB]

drm_info output = drmGetDevices: No such file or directory

[tigerjack]

@bl4ckb0ne

VGA compatible controller: Intel Corporation CometLake-U GT2 [UHD Graphics] (rev 02)
and
3D controller: NVIDIA Corporation TU117M [GeForce GTX 1650 Mobile / Max-Q] (rev a1)

[KaitlynEthylia]

@BridgerB have you managed to fix it? I'm getting the exact same issue

[bl4ckb0ne]

@tigerjack @BridgerB can you post the drm_info 1 output

[tigerjack]

@tigerjack @BridgerB can you post the drm_info 1 output

I am on 1.8 now and I didn't get these error messages in a while.

[bl4ckb0ne]

Alright, closing the issue then.

[bibanez]

Hello, I'm getting the same error in a fresh install of Arch with nvidia drivers and Sway version 1.8

How can I debug this?

[emersion]

The nvidia drivers are not officially supported.

[ii8]

I still have this problem running sway from a tty with AMD Radeon Vega graphics. It worked fine before updating to Sway 1.8 but the version I had before was a bit older, not 1.7.

I have rebooted a few times and it has not yet made a difference, so there's no evidence that it occurrs randomly for me.

Currently I am struggling to build drm_info, if it's necessary I can try again.

The full stderr log:

00:00:00.000 [INFO] [sway/main.c:338] Sway version 1.8
00:00:00.000 [INFO] [sway/main.c:339] wlroots version 0.16.1
00:00:00.001 [INFO] [sway/main.c:120] Linux hugo 6.1.12_1 #1 SMP PREEMPT_DYNAMIC Thu Feb 16 11:45:52 UTC 2023 x86_64 GNU/Linux
00:00:00.001 [INFO] [sway/main.c:136] Contents of /etc/os-release:
00:00:00.001 [INFO] [sway/main.c:120] NAME="Void"
00:00:00.001 [INFO] [sway/main.c:120] ID="void"
00:00:00.001 [INFO] [sway/main.c:120] PRETTY_NAME="Void Linux"
00:00:00.001 [INFO] [sway/main.c:120] HOME_URL="https://voidlinux.org/"
00:00:00.001 [INFO] [sway/main.c:120] DOCUMENTATION_URL="https://docs.voidlinux.org/"
00:00:00.001 [INFO] [sway/main.c:120] LOGO="void-logo"
00:00:00.001 [INFO] [sway/main.c:120] ANSI_COLOR="0;38;2;71;128;97"
00:00:00.001 [INFO] [sway/main.c:120] 
00:00:00.001 [INFO] [sway/main.c:120] DISTRIB_ID="void"
00:00:00.001 [INFO] [sway/main.c:108] LD_LIBRARY_PATH=
00:00:00.001 [INFO] [sway/main.c:108] LD_PRELOAD=
00:00:00.001 [INFO] [sway/main.c:108] PATH=/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/opt/texlive/2022/bin/x86_64-linuxmusl
00:00:00.001 [INFO] [sway/main.c:108] SWAYSOCK=
00:00:00.001 [INFO] [sway/main.c:376] Starting sway version 1.8
00:00:00.002 [INFO] [wlr] [libseat] [libseat/libseat.c:73] Seat opened with backend 'seatd'
00:00:00.002 [INFO] [wlr] [libseat] [libseat/backend/seatd.c:212] Enabling seat
00:00:00.002 [INFO] [wlr] [backend/session/session.c:109] Successfully loaded libseat session
00:00:00.002 [INFO] [wlr] [backend/session/session.c:473] Waiting for a DRM card device
00:00:10.012 [ERROR] [wlr] [backend/backend.c:217] Found 0 GPUs, cannot create backend
00:00:10.013 [ERROR] [wlr] [backend/backend.c:390] Failed to open any DRM device
00:00:10.108 [ERROR] [sway/server.c:73] Unable to create backend

[bl4ckb0ne]

Looks like you're missing a KMS driver

[ii8]

I'm not sure what you mean by missing a KMS driver, what driver could that be? I've not uninstalled anything, only updated sway and the kernel.

[emersion]

Somehow your kernel graphics driver doesn't load anymore. Check dmesg maybe.

[ii8]

I found these things in dmsg when booting linux 6.1:

[drm] amdgpu kernel modesetting enabled
[drm] BIOS signature incorrect 0 0
amdgpu: Invalid PCI ROM header signature: expecting 0xaa55, got 0xffff
amdgpu: unable to locate a BIOS ROM
amdgpu: Fatal error during GPU init 

I am able to start sway with an older kernel (6.0 instead of 6.1)
I always knew this BIOS was borked beyond repair and have tried to fix it before but there is no relevant update and it's proprietary.
In any case, clearly not a sway issue.

[blackmirroxx]

I am getting the same issue as "BridgerB commented on Nov 10, 2022" on the my new AMD radeon graphics card -> RX radeon 6650 xt
My OS is Gentoo, with kernel 6.1.31-gentoo (it used to work on 6.1.19)
It used to be working from tty with
$> dbus-run-session -- sway

I reinstalled all my XDG (e.g. xdg-utils...) related packages - no luck. As for now I sticking to my old kernel for now.

[guyuming76]

i just run into the same error on gentoo with DWL (based on wlroots-0.16.2)

turned out that i uninstalled the sys-auth/polkit recently.

I reinstalled this package and its dependency, and the issue fixed.

i wonder why the following line in backend.c need polkit to find gpus:
ssize_t num_gpus = wlr_session_find_gpus(session, 8, gpus);

UPDATE: if i set WLR_DRM_DEVICES=/dev/dri/card0 , i can start dwl without polkit and elogind