Mac Studio M2 Max: apple-drm exposes only HDMI connector, no DP connectors for Apple Studio Display

Our Neighbors Asahi Linux Asahi General
1

Hardware

  • Machine: Apple Mac Studio (2023)
  • SoC: Apple M2 Max
  • Model: Mac14,13
  • OS: Fedora Asahi Remix 42
  • Kernel: 6.19.14-400.asahi.fc42.aarch64+16k

Display

Apple Studio Display connected directly to the rear Thunderbolt port next to the Ethernet port.

Problem

The Apple Studio Display never receives a video signal.

If I connect an HDMI monitor, Fedora boots and works normally.

When I boot with only the Studio Display connected, the display remains black.

What I found

The DCP driver initializes correctly.

The Apple DRM driver is loaded successfully.

The USB Type-C subsystem is present.

However, only a single HDMI connector is exposed by DRM.

drm_info reports:

  • Driver: apple 1.0.0

  • Connector:

    • HDMI-A-1

  • No DP-* connectors are present.

/sys/class/drm contains only:

card1
card2
card2-HDMI-A-1
renderD128
version

The DRM debug state also reports only:

connector[45]: HDMI-A-1

No DisplayPort connector is ever created.

/sys/class/typec contains:

port0
port0-partner
port1
port1-partner
port2
port3
port3-partner

Kernel messages show DCP booting correctly and attempting a DisplayPort connection (dcp_dptx_connect(port=0)).

Question

Is USB-C / DisplayPort output expected to work on the Mac Studio M2 Max with the current Fedora Asahi Remix kernel?

Should DRM expose DP connectors on this machine, or is support for the Mac Studio still incomplete?

1 Like
2

DP alt mode hasn’t been implemented yet in the stable kernel. So video out only works on a native HDMI port.

DP alt mode is being tested for developers in the fairy dust tree branch. I’ve seen many people compile and report success with that, but no guarantees of course.

Side note: Fedora 42 has entered end-of-life last month, is there any reasons preventing you from updating to newer release?

3

Hi,

thanks for your answer, but really do you think that updating to newer release of Fedora (Fedora 44) could solve the problem?

4

No, updating won’t solve the problem. Display Port alt-mode is not in the stable kernel. The only way to get a display working over usb-c is to compile the fairydust kernel tree yourself (there are guides online if you want) or wait until it lands in the stable kernel (no ETA, it will arrive when ready)