Arch Linux

michi1990

Member

Registered: 2015-02-19

Posts: 10

[SOLVED] GDM doesn´t start unless i change to a different tty and back

I got a HP Envy x360 13-ay0251ng (AMD 4500U + Vega 6) with GDM and Gnome installed.

After the System has booted, the Screen goes black with a blinking cursor.
If i switch to another tty and check the status of the gdm.service it says: "active (running)" and the Logs are:

Started GNOME Display Manager.
GdmDisplay: Session never registered, failing
Child process -925 was already dead.
Child process -925 was already dead.
Child process -994 was already dead.

I tried the following without or partial success:
1) Disabling Wayland and using X11 -> problem stays the same but after tty switching it indeed shows X11 as Windowing System
2) Checking the entropy (was okay) and even installed haveged and enabled it -> same problem
3) Editing the service to:

 [Service]
 Type=idle

-> same problem

I tried lightdm and it works without changes. So i thought it could be a timing problem and added a 1 second sleep to the gdm.service and gdm starts now in the most cases.

Could anyone explain this behavior and can tell me a "true" fix instead of adding more time to my boot process ?

Here is the link to the full Dmesg: https://pastebin.com/amxnHP6r

any help would be appreciated

Last edited by michi1990 (2020-07-04 08:27:37)

michi1990

Member

Registered: 2015-02-19

Posts: 10

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

Update: It doesn´t matter if I use Kernel 5.7 or the mainline 5.8-rc3 kernel, the problem persists.

It also works more reliable after a non-coldstart.

eda2z

Member

From: Woodstock, IL

Registered: 2015-04-21

Posts: 69

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

Your problem sounds exactly like the one I was having as soon as I updated to the 5.7 kernel. In my case I have a Dell Precision 5720 AIO and it uses the i915 driver. I was able to fix my problem by adding the driver to /etc/mkinitcpio.conf inside MODULES=() and then rebuilding the kernel. I found the solution in the wiki.

michi1990

Member

Registered: 2015-02-19

Posts: 10

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

Thanks for your suggestion. I did add "amdgpu" to the Modules and it seems to work just fine.
Ill report back in a few days and close the Thread if it continues to work as its sometimes pretty random.

michi1990

Member

Registered: 2015-02-19

Posts: 10

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

Update: It still works. Thank you

marcD

Member

Registered: 2014-02-11

Posts: 5

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

I have the same issue for a while with my Dell latitude 5500 (i7-8665U + Mesa Intel UHD Graphics 620). I have tried the solutions 1)-3) without success, and the solution of adding the driver to the MODULES() seems not adapted to my case (mesa driver). Can you tell me how you  added a 1 second sleep to the gdm.service, which seems a good workaround ? Incidentally, do you know what difference it makes withe the Type=idle solution ?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,203

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

The modules driver can't not be adapted to your case as it is not talking about mesa but about your kernel module, so i915 for intel, amdgpu or radeon for the relevant amd generations, nouveau for nvidia (and a few more for the proprietary driver which are explained in it's own article)

But yes adding a one second delay will functionally have the "same" effect, as all these solutions have the goal of ensuring your graphics card/driver is ready before GDM attempts to use it.

marcD

Member

Registered: 2014-02-11

Posts: 5

Re: [SOLVED] GDM doesn´t start unless i change to a different tty and back

Editing the gdm service (sudo systemctl edit gdm) to

[Service]
Type=idle

makes the system boots about 50% of the time. On the other hand, adding 1 second delay by editing the service to:

[Service]
ExecStartPre=/bin/sleep 1

makes it works permanently ! I share this info which can be useful for others.