Bug 206387 - amdgpu with amdgpu.dc=1 and multiple monitors on DisplayPort keeps changing devices
Summary: amdgpu with amdgpu.dc=1 and multiple monitors on DisplayPort keeps changing d...
Status: NEW
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(DRI - non Intel) (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: drivers_video-dri
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-02-02 03:01 UTC by Alexandre Pereira
Modified: 2023-03-16 11:07 UTC (History)
3 users (show)

See Also:
Kernel Version: 5.5.0
Subsystem:
Regression: No
Bisected commit-id:


Attachments
xorg and dmesg log - boot 1 (21.61 KB, application/gzip)
2020-02-03 19:48 UTC, Alexandre Pereira
Details
xorg and dmesg log - boot 2 (21.56 KB, application/gzip)
2020-02-03 19:48 UTC, Alexandre Pereira
Details

Description Alexandre Pereira 2020-02-02 03:01:54 UTC
Hi,

I have an amd rx580 with 2 monitors connected by display port.
The 2 monitors are the same brand and model.

When using the amdgpu driver with amdgpu.dc=0, the device names ( DisplayPort-2 and DisplayPort-3 ) stay consistent, but when using amdgpu.dc=1, the device names change randomly ( or at least not consistent ).
They sometimes are DisplayPort-4 and DisplayPort-5 , sometimes DisplayPort-4 and DisplayPort-6, making me have to configure Xorg at every boot ( to correct the placement of the monitors, which is left and which is right ) and configure kde plasma and sway ( because they base their configurations on the device names ).

Currently I switched to using amdgpu.dc=1 because amdgpu.dc=0 locks computer after a wake up from suspend ( with amdgpu.dc=1 it does not ).

Thanks !
Comment 1 Alex Deucher 2020-02-03 16:24:22 UTC
Please attach your xorg log (if using X) and dmesg output.  dc support DP MST while the old dp=0 code does not.  With DP MST ports are added dynamically since you can have multiple DP monitors connected to a single physical port on the computer.
Comment 2 Alexandre Pereira 2020-02-03 19:48:04 UTC
Created attachment 287099 [details]
xorg and dmesg log - boot 1
Comment 3 Alexandre Pereira 2020-02-03 19:48:28 UTC
Created attachment 287101 [details]
xorg and dmesg log - boot 2
Comment 4 Alexandre Pereira 2020-02-03 19:50:07 UTC
Hi,

submitted two attachments, they have the xorg and dmesg log of bootup until login manager ( in this case sddm ) appears.

bootup 1 is the first reboot, and bootup 2 is a reboot right after getting the previous logs, nothing else was done in between.

Thanks.

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