5.15.5 on intel 6th gen CPU: long startup, long reboot, NO powerdown or suspend unless Vt-d is disabled.

[spxak1]

This is on 21.04 (system details at the end).

Lot's of edits on this sorry, but I put things together as it goes.

Slow after POST

Once the EFI stub is read, it takes a while to load the kernel. Normally this starts right away, it takes a good 8-10 seconds from EFI stub: Loaded initrd from command line option to actually load it and get started the boot process. With 5.13 this was instant.

Slow boot

Like a timeout, but actually these are the two oops.

Slow reboot

From sudo reboot to POST screen it takes under 10 seconds in 5.13, but over 27 seconds in 5.15.5. The time added is between the OS finishing and the laptop restarting (before POST). Which links to the next item

Here's the weird part: The laptop does not shutdown.

The process appears to be completed as usual (some output, I'll check later for details), the screen goes off, power button goes off, but keyboard backlight stays on, keyboard LEDs stay on and the fans stay on. I need to keep the power button for 4 seconds to turn off.

Same behaviour when suspending to RAM. Obviously there is no waking up from it as the power button is irresponsive, opening the lid won't change anything and only thing left to do is hold the power button for a hard power off and then restart as normal.

All of the above are resolved once VT-d is disabled in the bios. So something in this kernel doesn't agree with my laptop's (or CPU) VT-d. I will keep it disabled and keep testing (although I will need it back on for my VM's).

Info

NAME="Pop!_OS"
VERSION="21.04"
ID=pop
ID_LIKE="ubuntu debian"
PRETTY_NAME="Pop!_OS 21.04"
VERSION_ID="21.04"
HOME_URL="https://pop.system76.com"
SUPPORT_URL="https://support.system76.com"
BUG_REPORT_URL="https://github.com/pop-os/pop/issues"
PRIVACY_POLICY_URL="https://system76.com/privacy"
VERSION_CODENAME=hirsute
UBUNTU_CODENAME=hirsute
LOGO=distributor-logo-pop-os

Linux weywot 5.15.5-76051505-generic #202111250933~1638201579~21.04~09f1aa7-Ubuntu SMP Tue Nov 30 02: x86_64 x86_64 x86_64 GNU/Linux

[spxak1]

Update:

Removing acpi-call-dkms, and rebooting makes the oops stop. No more oops.

Edit: This seems to be the same problem as this. I'm still trying to figure out if the same workaround works. Edit: It is the same issue solved with the same workaround and while we wait for the new version of acpi-call-dkms (>1.2) to appear in the Ubuntu repositories.

[spxak1]

More testing on the rebooting/booting/poweroff/suspend issue.

I have done a separate installation of 21.10 beta to test what is coming my way soon.
Steps:

• Enable VT-d in bios
• Clean install 21.10 beta (.2 iso)
• 5.15.0 out of the box works fine. That is, booting is as fast as expected, ditto with rebooting. The system powers down properly and suspends and resumes as expected.
• 5.15.5 installed via apt-get.
• Same behaviour as with 21.04. From EFI stub to loading intramfs takes 12 seconds, reboot extremely slow to POST (i.e before loading the EFI stub), system will not power off or suspend but rather turn power LED off but keep keyboard LEDs + fans running (to no end).
• Reboot, disable VT-d.
• System behaves as expected (as with 5.15.0). All issues resolved.
• Reboot, enable VT-d.
• 5.15.6 mainline installed.
• Same behaviour as 5.15.5. No improvement.
• Reboot, disable VT-d.
• System behaves as expected (as with 5.15.0). All issues resolved.
• Reboot, enable VT-d.
• Remove 5.15.6 mainline, install 5.15.6 xanmod, reboot to xanmod
• System behaves as expected, all issues resolved. No need to disable VT-d.

So evidently with the same mainline kernel, xanmod does not cause this issue, while the vanilla mainline does.

I hope this helps.

Thanks.
*

[spxak1]

Some more confirmed reports of boot/reboot/poweroff/suspend issues here:

• https://www.reddit.com/r/pop_os/comments/r7p1k8/reboot_started_fully_shutting_down_and_then/
• https://www.reddit.com/r/pop_os/comments/r7wa6y/so_ive_run_from_every_distro_because_of_this/
• https://www.reddit.com/r/pop_os/comments/ra9auu/laptop_fails_to_resume_from_suspend_since_latest/
• https://www.reddit.com/r/pop_os/comments/radgvd/power_management_issues_after_one_of_the_recent/

This is narrowed down to 6th Gen intel CPUs.

[fouadzouraibi]

pop!_OS 21.04, after kernel 5.15 update, no suspend nor reboot or shutdown. Disable VT-d in bios seems to fix issue.
i7 6700hq gtx 960M

[BaronKrause]

I can confirm. Laptop with Intel 6th Gen CPU, same issues after Kernel 5.15.. Resolved after disabling VT-d.

[dmitriinor]

Same issue here, hotfixed by disabling VT-d in BIOS
Laptop: Thinkpad T460, i5 6300u
OS: Pop_OS! 21.04, kernel 5.15.5

[abrighton]

Same problem with Lenovo Thinkpad P70, OS: Pop_OS! 21.04, kernel 5.15.5.
Reverting to the previous 5.13 kernel is also a temporary workaround.

[spxak1]

I can confirm this is a problem with Haswell CPU's too. The issue is focused on graphics.

Here's a video of the issue: https://www.youtube.com/watch?v=XprqYp9iMtc

Solution is either to use a kernel older than 5.15.5 (5.15.4 and older works fine). Or to disable VT-d in the bios.

Thank you.

[polhaghverdian]

I have the same problem. 6th gen Xeon laptop.

Lenovo ThinkPad P50
Intel® Xeon(R) CPU E3-1505M v5 @ 2.80GHz × 8
NVIDIA Corporation GM107GLM [Quadro M2000M] / Quadro M2000M/PCIe/SSE2

[spxak1]

Jut to confirm, 5.15.8 has not fixed the issue.

Also to confirm that Xanmod, Manjaro and Fedora on the same kernel work fine.