Kubuntu 15.04 boot up to black screen, sddm seems to hang

[Sven Oostenbrink]

I installed my 15.04 clean. I did install a ppa that updated KDE to 5.3 after recommendations from the #kubuntu channel for having major problems with my install..

Now, 9/10 times, when sddm starts, it hangs with a black screen. I drop to a user shell, type sudo systemctl restart sddm.service, and I see something like "Starting version 219",and then a black screen.. I repeat this between 1 and 20 times and yay, I have a login screen!

Sometimes sddm shows the login screen right after boot, but it appears to be random. It seems it hangs about 9/10 times when started

[Kari Haapanen (karsta62)]

I have similar issues with sddm. Randomly it stops working and I end up to the sad black screen after logging in. So far I've managed to "fix" it by copying another working users .kde and .config directories, but that does not help anymore. Logging in as the other user works.
Check this bug:
https://bugs.launchpad.net/ubuntu/+source/sddm/+bug/1431332

[Shrikrishna (shrikrishna-holla)]

@sven Similar experience here. Installed Kubuntu 15.04, and every time I reboot I have to restart sddm ~10 times to get the login screen. Has anyone found a solution?

[Sven Oostenbrink (so-oostenbrink)]

Upon a recommendation on #kubuntu IRC I actually downloaded and installed 15.10 nightly build. It was either that, or returning to 14.10 since 15.04 was simply unworkable due to at least 15 other bugs of similar severity.. The install took a while to get right, I ran it from USB drive, it would not start up a few times, then it took a long time to get to the desktop from where I would start the install, but in the end: Totallyl worth it! 15.10 rocks like 15.04 should have. Basically everything works, as far as I can tell, and though once every 3 days, closing lid may cause a kernel panic, most of the system is as it should be.

So I've basically dropped 15.04 all together and I won't look back.

[Blaz (blaz-vrhnjak-3)]

Hello, I too have the same problem... The original KDE crashed numerous times and therefore I upgraded to KDE 5.3. Now the yesterday's system upgrades caused this issue - starting version 219 freeze. I have tried the solutions I could find (sudo dpkg --configure -a, sudo systemctl enable sddm.service -f & reboot, systemctl start sddm), I just did not repeat the thing 20 times but I'm desperate enough to try it now. Can this issue be fixed? It is quite frustrating as that is my "office" machine...

[Blaz (blaz-vrhnjak-3)]

Ok, doing sudo systemctl restart sddm.service 20 times does not cut it either:D New is only that that every 5-7 tries I get a message: Job for sddm.service failed. See "systemctl status sddm.service" and "journalctl -xe" for details.
Well, I'm no expert in this so help would be very much appreciated.

[Blaz (blaz-vrhnjak-3)]

Hello again! A few minutes ago I tried again and did sudo apt-get update&upgrade in terminal mode and some packages were updated. Now the boot works as it should. Thank you, developers!

[Twisted Lucidity (lucidlytwisted)]

System: Lenovo ThinkPad T430, Intel graphics (nvidia discrete available)
OS 15.04 -> 15.10

I think I am now experiencing this on a fresh upgrade to 15.10 from 15.04. In 10 boots I have managed to get to the login screen 3 times. Normally I just see the "Kubuntu" logo and then it goes blank.

No amount of restarting "sddm.service" has any effect.

I've looked through the logs and, from my limited understanding, nothing is amiss.
I am more than happy to run and tests or provide any logs that you might need because at the moment, the laptop is barely usable at the moment until I get this resolved.

[Twisted Lucidity (lucidlytwisted)]

After a lot of trouble, it seems like my issue is related to either bumblebee-nvidia or the gpu-manager generating and invalid xorg.conf. Either way, it does not appear to be sddm as withou bumblebee-nvidia I get a consistent login.

I guess the curse of nvidia's discrete card strikes again. :-(

[Sven Oostenbrink (so-oostenbrink)]

I have an NVIDIA GForce 680M card. To put it in the kind words of Linus: "Fuck you Nvidia"...

But seriously, can this please please please be fixed? Every login either I get a black screen at which I know I can type my password and login, or I get a black screen that does nothing, and then I have to service sddm restart a couple of times to get the login screen which is just worthless, really..

[Saeid Zebardast (saeidzebardast)]

Same problem!

Ubuntu 15.10
Geforce 960M

[Tzaphkiel (leroy-milamber)]

  * NVIDIA 970M
  * Kernel 4.4.2
  * Kubuntu 15.10
  * nvidia-361 nvidia-prime mesa-utils

I also get the black screen...
I have to switch to the first tty and do either:

```
sudo service sddm stop
rm -r ~/.local/share/kscreen
sudo service sddm start
```

or

after a reboot when the x fails to load (blank screen):
`sudo systemctl restart display-manager.service`

[Tzaphkiel (leroy-milamber)]

I have solved that issue by adding a kernel parameter in GRUB:

> sudo vi /etc/default/grub

Adding the following config:
GRUB_CMDLINE_LINUX_DEFAULT="rcutree.rcu_idle_gp_delay=1"

> sudo update-grub