https://bugs.freedesktop.org/show_bug.cgi?id=105725
--- Comment #4 from hjpriester@gmail.com --- Harry,
I have build a kernel using the:
git clone -b drm-next-4.17-wip git://people.freedesktop.org/~agd5f/linux
I did the clone about 2018-29-03 20:00 UTC
The warnings are still there. root@hjp2:~# dmesg | grep -i Warning [ 0.000000] ACPI BIOS Warning (bug): Optional FADT field Pm2ControlBlock has valid Length but zero Address: 0x0000000000000000/0x1 (20180105/tbfadt-658) [ 5.351226] WARNING: CPU: 1 PID: 491 at drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_base.c:64 dal_gpio_open_ex+0xc/0x30 [amdgpu] [ 5.353376] WARNING: CPU: 1 PID: 491 at drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_service.c:487 dal_ddc_open+0x2c/0xd0 [amdgpu]
I never get the hang during a boot. I will report that as a separate bug.
The display I am using is a IIYama Prolite XUB2792QSU using Displayport. It it a 27" 2560x1440 monitor. The distrubution is Slackware-current. ("pre 15.0")