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 askubuntu.com:
sudo nano /etc/default/grub- replace
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"withGRUB_CMDLINE_LINUX_DEFAULT="quiet splash amd_iommu=off" sudo update-grub- 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