simpledrm / lightdm race condition leads to black screen
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
systemd |
Unknown
|
Unknown
|
|||
lightdm (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned |
Bug Description
Config: Ryzen 5 5600X with Radeon 6700 XT GPU, a Navi22 card.
Using xUbuntu.
I had been daily driving the 24.04 nightly iso since March. About a week ago, I took a kernel update via apt and rebooted. The result was that the system would hard freeze to a black screen after the initial kernel messages cleared from the screen. Ctrl-Alt-Del did nothing, switching terminals (ctrl-alt-f#) did nothing, had to hard power off to regain control of the system.
I tried various fixes, none of which permanently stuck. This includes nomodeset in grub, rebooting into safe mode, checking for proprietary drivers. Safe mode allowed me to reboot once more into desktop, but then any subsequent reboots would result in a black screen lockup.
Suspending while able to use the desktop before reboot would cause a black screen lockup did not seem to cause any issues.
3 days before 24.04 was officially released, I reflashed the most recent installer iso to my thumbdrive, copied my home folder to my RAID and did a full wipe and fresh install.
First reboot after installation always went to the desktop. Subsequent reboots always resulted in a black screen lockup.
Memtest cleared without errors.
Again tried various fixes, nomodeset, safe mode, drivers. The only consistency was that regardless of what I could do to regain control or what I did differently when doing a wipe and reinstall, I would always reboot to a black screen.
Once 24.04 was officially released, I again did a full wipe and reinstall and encountered all of the above same issues as before.
After mentioning this in #ubuntu on libera, someone suggested a kernel downgrade.
24.04 as installed was using 6.8.0-31.31
Using Mainline, I downgraded to the next minor version below 6.8 that was considered stable. 6.7.10
Problem went away. No more black screen on boot, no more hard power offs required to be able to use my system again, no suspend issues. Was not necessary for me to do anything else to maintain a consistent successful reboot to desktop.
Did yet another full wipe and fresh install of 24.04, only installing Mainline upon first reboot to install 6.7.10, using Grub Customizer to edit the default grub option to boot the 6.7.10 kernel instead.
No issues.
I apologise that I did not collect logs during this process.
---
For those affected by this issue, this was my fix:
Install 24.04, reboot, at the desktop, open a terminal window and add the following PPAs:
sudo add-apt-repository ppa:cappelikan/ppa
sudo apt update
sudo apt install mainline
sudo add-apt-repository ppa:danielricht
sudo apt-get update
sudo apt-get install grub-customizer
Run mainline-gtk, install kernel version 6.7.10
run grub-customizer, move "Ubuntu, with Linux 6.7.10-
affects: | ubuntu → linux (Ubuntu) |
description: | updated |
description: | updated |
affects: | linux (Ubuntu) → lightdm (Ubuntu) |
Status changed to 'Confirmed' because the bug affects multiple users.