Bug 111261 - Screen remains black when 2 monitors are connected
Summary: Screen remains black when 2 monitors are connected
Status: NEW
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/AMDgpu-pro (show other bugs)
Version: DRI git
Hardware: Other All
: medium normal
Assignee: Default DRI bug account
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-07-30 13:56 UTC by Fab Stz
Modified: 2019-08-20 10:43 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
System information (part1) (13.06 KB, application/gzip)
2019-08-19 14:30 UTC, Fab Stz
no flags Details
System information (part2 = logs) (120.16 KB, application/gzip)
2019-08-19 15:29 UTC, Fab Stz
no flags Details

Note You need to log in before you can comment on or make changes to this bug.
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


Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.