Arch Linux

Please read this before reporting a bug:

Do NOT report bugs when a package is just outdated, or it is in Unsupported. Use the 'flag out of date' link on the package page, or the Mailing List.

REPEAT: Do NOT report bugs for outdated packages!

FS#63763 - [gdm] GDM 3.34 just shows a black screen with a blinking cursor in the upper left

Attached to Project: Arch Linux
Opened by Martin (mort96) - Saturday, 14 September 2019, 14:43 GMT
Last edited by freswa (frederik) - Saturday, 22 February 2020, 16:22 GMT
Task Type Bug Report
Category Packages: Testing
Status Assigned
Assigned To Jan de Groot (JGC)
Jan Alexander Steffens (heftig)
Architecture All
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 13
Private No



With GDM 3.32, GDM works as expected. With GDM 3.34, it just shows a black screen. Automatic login still works.

Steps to reproduce:

Install gdm 3.34, enable gdm, reboot.

I'm running gdm on a laptop with an Intel i7-8705G and a 4k screen.
   gdm-log.txt (123.1 KiB)
This task depends upon

Comment by Marko G (VxMxPx) - Friday, 20 September 2019, 08:30 GMT
I'm experiencing the same problem. If you go to tty2 and do `sudo systemctl restart gdm.service` it does work normally, and you can login.

EDIT: Actually for me, after some waiting period it does show up on its own, it just needs long time.
Comment by hsingyun (zhkailing) - Saturday, 21 September 2019, 19:11 GMT
the same problem. GDM took a long time to start.

AMD 3900x and Nvidia 2080Ti
Comment by Jonas T. (dargmuesli) - Monday, 23 September 2019, 22:00 GMT
Same, `sudo systemctl restart gdm.service` did not help. I see a white cursor (underscore) in the top left corner that starts to flash after a second.
Comment by Rufat B. (dsh) - Monday, 23 September 2019, 23:13 GMT
Same for me! Either it just doesn't show up or only after a very long while. Maybe it is a graphics card issue as I also have a 2080 Ti. Restarting the service also doesn't help most of the time.
Comment by Gabor Sz. (stiefel) - Tuesday, 08 October 2019, 02:19 GMT
I can confirm it as well on a Thinkpad E560. Booting LTS kernel solves the issue, and is able to start GNOME on wayland. On 5.3 after 1.5 minutes timeout GNOME is started with X. Early KMS had no influence on it either (at least with i915 and intel_agb).
Comment by shihua (shihua) - Monday, 21 October 2019, 07:14 GMT
Comment by Marti (intgr) - Sunday, 29 December 2019, 22:53 GMT
This is possibly the same issue as

Possible workarounds:
* Try out the patch linked in the above bug. PKGBUILD & patches here:
* Many users in forums are recommending "early KMS" to fix GDM issues:
Comment by Jonas T. (dargmuesli) - Monday, 30 December 2019, 02:34 GMT
I tried setting "i918", then with "intel_agp", then with "nouveau" for early KMS, but that didn't change the outcome. Upgrading all packages to 3.34, then cloning the linked trunk and reinstalling gdm with "makepkg -si" did not solve the issue for me as well, sadly. Tell me if I did something incorrectly or if any debug info may help you. Thanks for your comment, still!
Comment by Maxim Moseychuk (fshp) - Sunday, 24 May 2020, 01:53 GMT
Please change the category to "Packages: Extra"
Comment by Vladislav Pashinskikh (pashinskikh) - Saturday, 13 June 2020, 06:22 GMT
Looks like I started to have the same issue with GDM 3.36.2-1. After boot it just shows a black screen with a blinking cursor in the upper left.
If I go to tty2, and back to tty1 it loads imidiatelly.

Here's what systemd shows:
Jun 13 08:57:29 elitebook systemd[1]: Started GNOME Display Manager.
Jun 13 08:57:30 elitebook gdm[625]: GdmDisplay: Session never registered, failing
Jun 13 08:57:30 elitebook gdm[625]: Child process -698 was already dead.
Jun 13 08:57:30 elitebook gdm[625]: Child process -698 was already dead.
Jun 13 08:57:30 elitebook gdm[625]: Child process -737 was already dead.
Jun 13 08:57:53 elitebook gdm-password][1058]: gkr-pam: unable to locate daemon control file
Jun 13 08:57:53 elitebook gdm-password][1058]: gkr-pam: stashed password to try later in open session
Jun 13 08:57:53 elitebook gdm-password][1058]: pam_unix(gdm-password:session): session opened for user pashinskikh by (uid=0)
Jun 13 08:57:53 elitebook gdm-password][1058]: gkr-pam: gnome-keyring-daemon started properly and unlocked keyring
Jun 13 08:57:57 elitebook gdm[625]: Child process -805 was already dead.
Comment by Mathias Anselmann (matse) - Wednesday, 07 October 2020, 14:36 GMT
Same problem on my laptop here with just an integrated graphic card, in Wayland as well in Xorg mode.
Switching to terminal and back solves the problem... still a nasty workaround.
Comment by Marti (intgr) - Sunday, 11 October 2020, 20:31 GMT Comment by Robert Strube (rstrube) - Friday, 30 October 2020, 23:14 GMT
Hi everyone,
I've also run into this extremely annoying bug. At first I thought it was related to not having enough entropy at boot time, so I installed rng-tools and enabled rngd.service, but that didn't solve the issue.

I ultimately figured out that adding a delay to the gdm.service allowed me to start GDM consistently. To do this I inserted "ExecPreStart=/bin/sleep 2" line into the gdm.service file, so it looks like:

... more ...
ExecStartPre=/bin/sleep 2
... more ...

In order to prevent this change from being overwritten, I created a pacman hook that will always insert the delay after a gdm package update.

Hook is installed here: /etc/pacman.d/hooks/gdm.hook

And the hook looks like:


Description=Adds a small delay to /usr/lib/systemd/system/gdm.service to work around bug
Exec=/usr/bin/sed -i '/^\[Service\]/a ExecStartPre=\/bin\/sleep 2' /usr/lib/systemd/system/gdm.service

This seems to work well for me, and I don't have to reapply the fix after updating GDM.

I hope this helps others.
Comment by Darren Miller (darrenm) - Saturday, 31 October 2020, 17:27 GMT
thanks for that 2 second sleep tip - works perfectly for me. It's crude but I prefer it to the things other distros seem to be doing to solve the same problem