Arch Linux

Description:

intel-ucode 20191113-1 causes a lockup when rebooting a Dell Precision 5820 workstation with an Intel Xeon W-2145 CPU. The system cold boots fine, but once the system is running, a reboot will cause a lockup when the kernel is reloaded. This is a regression from intel-ucode 20190918-1 and affects more than one bootloader and at least the linux, linux-zen and linux-lts kernels.

Additional info:
* package version(s)

Affected version: intel-ucode 20191113-1
Previous working version: intel-ucode 20190918-1

Bootloaders affected: systemd-boot (from systemd 243.78-2), rEFInd (from refind-efi 0.11.3-1)
Kernels affected: linux (5.3.11.1-1), linux-lts (4.19.84-1), linux-zen (5.3.11.1-1)

* config and/or log files etc.

No log files are available; the hang occurs before the initcpio can run any hooks.

For systemd-boot, the loader entry is:
title Arch Linux
linux /vmlinuz-linux
initrd /intel-ucode.img
initrd /initramfs-linux.img
options root=UUID=[masked] rw
options consoleblank=600
options audit=0

For rEFInd, the loader entry is the default created by refind-install. rEFInd was not configured to load the microcode; it locked up after warm rebooting from an initial boot using systemd-boot that loaded the microcode from a cold boot.

* link to upstream bug report, if any

There does not appear to be a corresponding upstream bug report.

Steps to reproduce:

1. Install any of the kernels listed above (other kernels may be similarly affected).
2. Configure systemd-boot to boot with a loader entry like that above.
3. Install intel-ucode 20191113-1 and make sure systemd-boot will attempt to load the microcode.
4. Cold boot the system; everything should boot as expected.
5. Invoke "shutdown -r now".
6. After systemd-boot selects the kernel, the system should hang on the "SHA256 validated" message.
7. Forcibly power down the system.
8. [In my case, attempted to turn on the system at this point will cause the fans to spin, then the system to immediately shut itself down; powering on a second time will bring up the system as expected.]
9. Replace intel-ucode 20191113-1 with version 20190918-1 and confirm that the system boots and reboots as expected.