Bug 108516 - Device name mismatch with /sys/class/drm
Summary: Device name mismatch with /sys/class/drm
Alias: None
Product: xorg
Classification: Unclassified
Component: Server/DDX/Xorg (show other bugs)
Version: unspecified
Hardware: Other All
: medium major
Assignee: Xorg Project Team
QA Contact: Xorg Project Team
Depends on:
Reported: 2018-10-22 19:34 UTC by JM9
Modified: 2018-10-24 08:18 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:

xorg log (31.87 KB, text/plain)
2018-10-23 18:26 UTC, JM9
no flags Details

Description JM9 2018-10-22 19:34:23 UTC
In /sys/class/drm device names are:
card0-DP-1  card0-DP-2  card0-DP-3  card0-eDP-1  card0-VGA-1

However, xrardr reports:
eDP1, VGA1, DP-1-1, DP-1-2, DP-1-3

This is on an Optimus laptop with Hybrid Graphics enabled. With Hybrid Graphics disabled, xrandr reports correct device names.

This started with xorg version 1.20
Comment 1 Michel Dänzer 2018-10-23 09:14:26 UTC
Please attach the corresponding Xorg log file.
Comment 2 JM9 2018-10-23 18:26:54 UTC
Created attachment 142159 [details]
xorg log
Comment 3 JM9 2018-10-23 18:27:11 UTC
(In reply to Michel Dänzer from comment #1)
> Please attach the corresponding Xorg log file.

xorg log attached.
Comment 4 Michel Dänzer 2018-10-24 08:18:04 UTC
According to the Xorg log file, eDP and VGA are connected to the integrated Intel GPU, used as primary by Xorg, whereas DP-[123] are connected to the discrete Nvidia GPU, used as a secondary by GPU. Outputs of secondary GPUs get a suffix (like -1 in this case) to avoid output name clashes between GPUs.

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