Console Freezes during boot on Iris 6200
From kernel 5.7.5 - 5.8rc3 (have not tried any older 5.7 kernels) console freezes rather early during boot. Around local-fs.target. The boot itself continues, I can login blindly or via ssh. However, I cannot gracely reboot, I need to invoke the power button for ~10sec. When blindly switching tty and log in and run "startx", nothing happens either. Kernel 5.6.15 is running without any problems.
This issue seems to be specific to the Intel Iris, as on a UHD605 and Skylake GT2 [HD Graphics 520] I do not experience this problem. What stands out from the log, that the lines:
kernel: [drm] Initialized i915 1.6.0 20190822 for 0000:00:02.0 on minor 0 kernel: fbcon: i915drmfb (fb0) is primary device kernel: i915 0000:00:02.0: fb0: i915drmfb frame buffer device
are missing and that journal also reports:
systemd-udevd: 0000:00:02.0: Worker  processing SEQNUM=2913 is taking a long time systemd-udevd: 0000:00:02.0: Worker  processing SEQNUM=2913 killed
With 00:02.0 of course being the intel gpu.
Does however report, that no error states have been collected.
Handle 0x0002, DMI type 2, 15 bytes
Base Board Information
Product Name: Z97 Extreme6/3.1