When plugging in a display (thunderbolt 3 - hdmi using displayport protocol) the second display sink is not detected.
Version-Release number of selected component (if applicable):
How reproducible:
Can be reproduced with a thunderbolt 3 notebook and an hdmi display
Steps to Reproduce:
Plug display into hdmi cable
Plug usbc dongle into hdmi cable
Plug dongle with hdmi cable into notebook
Observe Switchboard -> display for additional displays
Actual results:
When plugging in the display, no second display appears in switchboard
Expected results:
When plugging in the display, the 2nd display should appear in switchboard just as it does gnome-settings
Additional info:
Dell XPS 13 (9350) with Dells official usbc - hdmi dongle (uses displayport protocol over hdmi plug)
USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
Additional Notes
I noticed that this works on a dell docking station and when plugged into an HDMI monitor that can display edid information.
In the instance that I reported above I saw the kernel pick up the display sink, the xhci driver attempt mtp mode and finally pull in incomplete edid information from the projector and nothing after that.
I need to test further to see if this happens with app projectors or all VGA displays, but think displays should see the display advertise it and show the 2nd screen as disabled and require the user to pick the correct resolution (only when edid information cannot be found).
Description of problem:
When plugging in a display (thunderbolt 3 - hdmi using displayport protocol) the second display sink is not detected.
Version-Release number of selected component (if applicable):
How reproducible:
Can be reproduced with a thunderbolt 3 notebook and an hdmi display
Steps to Reproduce:
Actual results:
When plugging in the display, no second display appears in switchboard
Expected results:
When plugging in the display, the 2nd display should appear in switchboard just as it does gnome-settings
Additional info:
Dell XPS 13 (9350) with Dells official usbc - hdmi dongle (uses displayport protocol over hdmi plug)
USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
Additional Notes
I noticed that this works on a dell docking station and when plugged into an HDMI monitor that can display
edidinformation.In the instance that I reported above I saw the kernel pick up the display sink, the xhci driver attempt mtp mode and finally pull in incomplete edid information from the projector and nothing after that.
I need to test further to see if this happens with app projectors or all VGA displays, but think displays should see the display advertise it and show the 2nd screen as disabled and require the user to pick the correct resolution (only when edid information cannot be found).