I am currently using Linux Fedora 37 on my iMac 2015 A1418. Unfortunately sleep mode and turning off computer doesn’t work properly - after clicking the buttons, computer restarts and that’s all.
Please tell me what I need to provide so that the problem can be detected. I am new to Linux!
MacBook Pros introduced in 2015 suffer from a similarly annoying issue caused by an unused PCIe root port that Apple forgot to disable in the firmware. The root port is invisible to macOS because it is not enumerated in the ACPI tables, but Linux discovers and initializes it, thereby breaking suspend and power off on these machines. Chen Yu has posted a workaround patch which is not yet in mainline but already included in distributions such as Ubuntu.
Does adding reboot=pci or reboot=acpi to the kernel command line help?