screen wakes up 10 seconds after blanking with i915 on 11th gen intel cpu with Iris XE
I recently upgraded one of my computers from an older 3rd gen intel cpu to a new i5-11400 on an Asus PRIME Z590M-Plus motherboard on the latest 0820 bios. Both the old and new iteration of this computer were using the intel integrated graphics with the i915 driver. After the motherboard/cpu upgrade, my monitor has not been turning off correctly. It will go to sleep, then wake up after 10 seconds. Same OS install, same screen blanking settings as before, the only real difference is the new mobo/cpu/ram.
This seems to be a problem both within and outside of X, the monitor used to shut-off just fine from the console via the consoleblank=300 kernel parameter, but I also experience the same symptoms within X. Running "sleep 1;xset dpms force off" within X will sometimes get it to shut off for good, but not consistently, and it will often just come back on after 10 seconds, same as just letting it idle.
I am running arch linux with kernel 5.12.8 but I compiled a kernel with drm-tip and the problem persisted. Here is a copy of dmesg with the drm debug setting turned on with 5.13.0-rc3-1-drm-tip-git-g7f5eac3354e9. I did "setterm --blank 1" from the console and waited 1 minute to let it blank before capturing this output.