#Gdm: Child process -738 was already dead. No Nvidia involved.

1 messages · Page 1 of 1 (latest)

wary swan
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I'm trying to set up a new system with amdgpu and, for some reason, GDM won't start. I'm getting exactly the symptoms mentioned here https://wiki.archlinux.org/title/GDM#Black_screen_on_AMD_or_Intel_GPUs_when_an_NVidia_(e)GPU_is_present which is to say a black screen with a blinking cursor and error messages similar to this one: Gdm: Child process -738 was already dead.

The only problem is that there is no nvidia gpu of any kind on my system and no nvidia (or nouveau) module has been loaded. My graphics card is a Radeon RX 6600 and the onboard graphics for the mobo is (as far as I can tell) an intel one. I also can't see any evidence of an intel module being loaded either.

There are no logs in /var/gdm. I have enabled debug in gdm settings, but still no logs in there.

Any logs which would be helpful - please let me know.

GDM
earnest herald
earnest herald
wary swan
earnest herald
wary swan
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Looks like there is a DRM issue. Also - I don't know why it's trying ot set up multihead...

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On top of all of which, I'm hoping ot use wayland, which should mean it shouldn't even try to use xorg unless it's failing to start waylanbd right?

earnest herald
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.s ix

strong cliffBOT
wary swan
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thanks - good tip

earnest herald
wary swan
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I'm actually hoping to run wayland, but for reasons I can't fathom that's not working and gdm is trying to launch xorg - which is also then failing. But it is an amdgpu, yes.

earnest herald
wary swan
earnest herald
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I'm actually hoping to run wayland
GDM can be forced to use Wayland

ln -sf /dev/null /etc/udev/rules.d/61-gdm.rules
wary swan
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I thought it tried to by default anyway?

earnest herald
earnest herald
# wary swan https://pastebin.com/e6gcq7Fi

[ 1083.142] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 1083.142] (II) Platform probe for /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:00.0/0000:03:00.0/drm/card0
[ 1083.181] (--) PCI:*(3@0:0:0) 1002:73ff:1849:5217 rev 199, Mem @ 0x4200000000/8589934592, 0x4100000000/2097152, 0x80000000/1048576, I/O @ 0x00003000/256, BIOS @ 0x????????/131072

It seems you don't have an integrated GPU from xorg log

wary swan
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There should be an onbaord one, but my main GPU is an added graphics card

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I think the onboard one might be intel, but it's hard to tell.

earnest herald
wary swan
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Interesting. There's definitely a VGA and HDMI output on the mobo

earnest herald
wary swan
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doesn't seem to - results in exactly the same behaviour.

earnest herald
wary swan
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yes. There's only one monitor and it's connected to the display port of the GPU via a VGA-displayport adapter (monitor is only VGA and GPU doesn't have VGA out). If I boot into the bios then I get a display.

earnest herald
wary swan
earnest herald
wary swan
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It doesn't return a url...

earnest herald
wary swan
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ok - it returns very quickly with nothing, but I can wait if it'll turn up a url eventually...?

earnest herald
wary swan
earnest herald
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sudo pacman -Qkk dbus
wary swan
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ah yes - that is missing. I'll fix that and see if it makes a difference.