Ubuntu Freeze After Suspend Fix


I recently got a new Lenovo ThinkPad T14 laptop and decided to install Zorin 16.1 on it. But, consistently, after suspending, the laptop froze…

The problem

After finishing my work, I would like to put the laptop in a low-power state while keeping its current state, so I can resume easily the next day. For some reason after putting the laptop in to standby (suspend) mode and then waking it up, it freezes.

The result is that I either keep the laptop running at the end of the workingday, which is energy consuming, or I need to turn it off completely which is not user-friendly. Having worked with Windows laptops hibernating or M1 based MacBooks that remain in low-energy standby modes, this is a real let-down.

The solution

So I searched for a solution and found one that worked on

  1. sudo nano /etc/default/grub
  2. replace GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amd_iommu=off"
  3. sudo update-grub
  4. reboot the machine

Background on amd_iommu

I wondered what this argument would do and looked it up.

According to the Linux Kernel Documentation it is a kernel argument to pass parameters to the AMD IOMMU driver. Setting it to off disables initializing it.

The AMD IOMMU driver is responsible for the AMD I/O Virtualization Technology and handles handing over control of host hardware to virtualized hosts. See TechDoc 48882_IOMMU.pdf for more details.

October 15, 2022