Created attachment 141265 [details]
Dmesg from boot with Kernel 4.19 prerelease
I have already reported this on Redhat Bugzilla, so if more information is
needed, that may be a good place to look at comments:
https://b=
ugzilla.redhat.com/show_bug.cgi?id=3D1594488
Since the change to using dc in the kernel I am getting a blank screen with
trying to boot my ultrawidescreen monitor.
As a workaround I can use amdgpu.dc=3D0, but this hits al earlier big where=
at
native resolution the display output is garbled (links in Redhat Bugzilla
attach to another big report, youtube video of the same).
I am attaching dmesg output from
4.19.0-0.rc0.git8.1.vanilla.knurd.1.fc28.x86_64 with and without amdgpu.dc=
=3D0
I have noticed a couple of entries in the dmesg without the amdgpu.dc=3D0:
kernel: [drm] add ip block number 4 <dm>
with amdgpu.dc=3D0 it is:
kernel: [drm] add ip block number 4 <dce_v11_0>
The other ip address block entries are identical.
with amdgpu.dc=3D0 I get this section:
Aug 22 23:46:22 kernel: [drm] PCIE GART of 256M enabled (table at
0x000000F400900000).
Aug 22 23:46:22 kernel: [drm] Supports vblank timestamp caching Rev 2
(21.10.2013).
Aug 22 23:46:22 kernel: [drm] Driver supports precise vblank timestamp quer=
y.
Aug 22 23:46:22 kernel: [drm] AMDGPU Display Connectors
Aug 22 23:46:22 kernel: [drm] Connector 0:
Aug 22 23:46:22 kernel: [drm] DP-1
Aug 22 23:46:22 kernel: [drm] HPD5
Aug 22 23:46:22 kernel: [drm] DDC: 0x4868 0x4868 0x4869 0x4869 0x486a 0x4=
86a
0x486b 0x486b
Aug 22 23:46:22 kernel: [drm] Encoders:
Aug 22 23:46:22 kernel: [drm] DFP1: INTERNAL_UNIPHY1
Aug 22 23:46:22 kernel: [drm] Connector 1:
Aug 22 23:46:22 kernel: [drm] HDMI-A-1
Aug 22 23:46:22 kernel: [drm] HPD3
Aug 22 23:46:22 kernel: [drm] DDC: 0x4874 0x4874 0x4875 0x4875 0x4876 0x4=
876
0x4877 0x4877
Aug 22 23:46:22 kernel: [drm] Encoders:
Aug 22 23:46:22 kernel: [drm] DFP2: INTERNAL_UNIPHY1
Aug 22 23:46:22 kernel: [drm] Connector 2:
Aug 22 23:46:22 kernel: [drm] DVI-D-1
Aug 22 23:46:22 kernel: [drm] HPD4
Aug 22 23:46:22 kernel: [drm] DDC: 0x4878 0x4878 0x4879 0x4879 0x487a 0x4=
87a
0x487b 0x487b
Aug 22 23:46:22 kernel: [drm] Encoders:
Aug 22 23:46:22 kernel: [drm] DFP3: INTERNAL_UNIPHY
Aug 22 23:46:22 kernel: [drm] Chained IB support enabled!
but without amdgpu.dc=3D0 only the first and last line of that section appe=
ar.
Later down without the amdgpu.dc=3D0 I also get the following message:
kernel: [drm] Cannot find any crtc or sizes
This may also be similar to bug
https://bugs.freedesktop.org/show_bug.=
cgi?id=3D105880 but that is for laptop
panels on LVDS while this issue is with a discrete RX460 graphics card on H=
DMI