Ubuntu 18.04 LTS boot hangs after 1st update

[Sylvain Vedrenne]

I installed Ubuntu 18.04 LTS on my new ASUS UX533F laptop.

The installation seemed successful at first - except for the audio not working - but then:

- open "Software Updates"
- accept to install all available updates
- reboot
  => The system hangs on the purple screen

If I press the space bar before the ASUS logo at boot, I can access the GRUB menu and select the Recovery Mode - same problem in Recovery Mode: the system hangs on the purple screen.

To avoid instability issues with the graphics card NVidia GeForce MX150, I had added 'nouveau.modeset=0' to /etc/default/grub for the Linux command line before doing the first software update and reboot.

/etc/default/grub
...
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nouveau.modeset=0"
...

But it doesn't prevent this boot hanging problem. And it is not the cause of this boot hanging problem.

Adding dis_ucode_ldr to the Linux command line lets me to go past the GRUB screen and boot Ubuntu 18.04 again. But this is only a workaround. We need a proper fix.

[Sylvain Vedrenne (bludzee)]

Duplicate of bug #1829620:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1829620

[Sylvain Vedrenne (bludzee)]

Since then, this laptop model ASUS UX533F is supported by Ubuntu 18.04 LTS as far as I know.
Last time I tried, this parameter had to be added to the Linux kernel command line:
dis_ucode_ldr

In April 2020, I switched to Ubuntu 20.04 LTS, which works with this laptop model ASUS UX533F.