Bug 111261

Summary: Screen remains black when 2 monitors are connected
Product: DRI Reporter: Fab Stz <fabstz-it>
Component: DRM/AMDgpu-proAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED MOVED QA Contact:
Severity: normal    
Priority: medium    
Version: DRI git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
System information (part1)
none
System information (part2 = logs) none

Description Fab Stz 2019-07-30 13:56:15 UTC
With 2 monitors (one on VGA, one on DVI-D), screen turns black while loading system in console
When only 1 monitor connected to VGA everything is fine.

There is no problem with kernel 5.2 or with amdpgu-dkms 19.10 on debian buster (linux 4.19)

It happens only with amdpgu-dkms 19.20 or 19.30 (on debian buster - kernel 4.19)
For 19.20 I applied my patch from https://bugs.freedesktop.org/show_bug.cgi?id=111103, which is merely the same as the code in 19.30
Comment 1 Fab Stz 2019-08-18 08:04:22 UTC
Bug still present in amdgpu-pro-19.30-855429-ubuntu-18.04

Last working version is amdgpu-pro-19.10-785425-ubuntu-18.04
Comment 2 Alex Deucher 2019-08-19 13:18:06 UTC
Please attach your xorg log (if using X) and your dmesg output.  What GPU are you using?
Comment 3 Fab Stz 2019-08-19 14:17:46 UTC
Thanks for your interest in that issue.

How could I do that with nothing visible on my monitors ? Is there any parameter I can add to the kernel to keep a log ?
Comment 4 Fab Stz 2019-08-19 14:30:12 UTC
Created attachment 145098 [details]
System information (part1)

Please find attached:
- basic configuration details.
- addition information

As instructed here :
https://amdgpu-install.readthedocs.io/en/latest/install-bugrep.html
Comment 5 Fab Stz 2019-08-19 15:29:45 UTC
Created attachment 145101 [details]
System information (part2 = logs)

I could get the logs/info through SSH
There was no Xorg.log probably because the system didn't start X

There is no dedicated GPU on my system but an APU/CPU with integrated graphics : 
"AMD Athlon 200GE with vega graphics"

BTW, running kernel 5.2.x was fine (both monitors had something displayed)
Comment 6 Fab Stz 2019-08-20 10:43:52 UTC
The issue seems to be related to these calls in file
amdgpu-19.30-855429/amd/display/amdgpu_dm/amdgpu_dm.c

twice:
kcl_drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux);

once:
kcl_drm_dp_cec_set_edid(&aconnector->dm_dp_aux.aux,
					    aconnector->edid);

If I delete them the display works also with 19.30
Comment 7 Martin Peres 2019-11-19 08:00:44 UTC
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