Live USB Installer not working Samsung Notebook 9 Pro 15"

[Robert Davenport]

Live USB made from ubuntu-20.04-desktop-amd64 fails to boot. System hangs with watchdog: BUG: soft lockup - CPU# and rcu: INFO: rcu_sched self-detected stall on CPU.

System specs:
Intel(R) i7-7500U running AMD discrete graphics

Have tested the Live USB on other systems with no problems, appears to be hardware related with the Samsung Notebook 9 Pro and other systems (Dell, etc.)

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1878726

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Robert Davenport (fairhb)]

Unable to load kernel to generate log file.

[Kai-Heng Feng (kaihengfeng)]

Could you please try older iso like 16.04 or 18.04?

[Robert Davenport (fairhb)]

I created a live USB of my system using systemback before trying to upgrade from 19.10 to 20.04. My live USB backup works fine. I tried a Fedora 31 live USB and it works fine. I also used different methods to create the 20.04 Live USB thinking it might have been a corrupt iso. I tested the last live USB on my other Samsung Notebook 9 Pro 13" (different hardware) and it works fine. Both systems are dual-boot (Win10/Linux).

Reviewing the system log as it attempts to load, I believe the issue is with the discrete graphics chip in the CPU. There is a VGA error related to the AMDGPU.

drm:amdgpu_init [amdgpu]] *ERROR* VGACON disables amdgpu kernel modesetting

[Robert Davenport (fairhb)]

I tried booting in safe graphics mode. It gets stuck in an endless loop:

watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u8:3:194]
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: $0-...: (14999 ticks this GP) idle=736/1/0x4000000000000002 softirq=5356/5356 fqs=7398
[FAILED] Failed to start udev Wait for Complete Device Initialization

INFO: task kworker/2:1:37 blocked for more than 120 secs...

[Kai-Heng Feng (kaihengfeng)]

Please attach full dmesg.

[Robert Davenport (fairhb)]

@kaihengfeng, not sure how to capture dmesg, as the boot process never completes preventing me from accessing a command line. Also, I am unable to switch to another TTY session. Can you please provide guidance or direct me to a article that explains how to capture the log?

[Obert Wood (bowood)]

I have same laptop with same problem on 20.04. Works great on 19.10. Every once in awhile I can get it to systemd.unit=emergency.target. But it hangs soon after if even doing an "lsmod".

[Robert Davenport (fairhb)]

Live USB fails to boot or provide command line for submitting log file. I am attaching a video (excuse the poor quality) that captures the load sequence. Hopefully this is insightful enough for helping to troubleshoot.

[Kai-Heng Feng (kaihengfeng)]

It's most likely a driver bug, which blocks systemd-udevd. Have you tried older Ubuntu release like 18.04 or 16.04?

[Robert Davenport (fairhb)]

Older version Live USBs work. I am currently running on a Live Backup 19.10 to write this. I am only having an issue with 20.04.

[Kai-Heng Feng (kaihengfeng)]

If the USB has enough storage, would it be possible for you to do a kernel bisection?

First, find the last -rc kernel works and the first -rc kernel doesn’t work from http://kernel.ubuntu.com/~kernel-ppa/mainline/

Then,
$ sudo apt build-dep linux
$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
$ cd linux
$ git bisect start
$ git bisect good $(the working version you found)
$ git bisect bad $(the non-working version found)
$ make localmodconfig
$ make -j`nproc` deb-pkg
Install the newly built kernel, then reboot with it.
If it still have the same issue,
$ git bisect bad
Otherwise,
$ git bisect good
Repeat to "make -j`nproc` deb-pkg" until you find the offending commit.

[Robert Davenport (fairhb)]

Hi @kaihengfeng,

I am not familiar with kernel/git bisection and was unable to do what you asked, partly because I couldn't boot into linux/ubuntu to begin with, and updating the kernel from 19.10 wouldn't test all the other services that could be at play.

However, after repeated efforts or restarting my system, I was able to finally get the live USB to get past the blocker (still not sure why it was blocked from booting). I wish I could explain what steps I took in order to get to this stage, but it was truly a luck of multiple reboots switching between safe kernel and nor kernel, enabling and disabling secure-boot until the system corrected itself and booted from the liveUSB. From the successful session, I was able to install a clean version of 20.4 LTS, but have had the same issue when trying to reboot, that I was having with the live USB.

Because I was able to finally boot into the Live USB without any system changes, my thought is the problem is not with the kernel (otherwise, I would have never have gotten it to boot, regardless of how many attempts through restart). It consistently seems to fail during a systemd initialization, with uuid, as if the UEFI partition is not found. Checking fstab, everything seems to be correct. Looking at the log files, unfortunately, they only reflect the successful boot. All of my previous failed attempts to boot in 20.04 aren't present.

At this point, I am not sure how I can help to troubleshoot this issue, but it is still an issue to consistently be able to boot into 20.04, even though I was able to install from the live USB.

Any recommendations on what to try, will be gladly appreciated.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]