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I'm trying to use a USB-C to HDMI cable (not adapter) to connect to an external monitor with no luck. The display is detected, can be selected, and displays video but the video is not displayed correctly. I'm not sure the correct terminology to describe this but it looks like this:

Strange colors

Another Example

  • I'm using an acer switch alpha 12
  • APU Graphics: Intel HD Graphics 520
  • the intel driver is otherwise working well.
  • The apple display adapter (USB-C to HDMI/USB 3.0/USB-C) works perfectly.
  • This same cable works with Windows.

Any Ideas?

EDIT: This has been confirmed with no resolution known. Seems to be related to the i915 driver. https://bugs.launchpad.net/ubuntu/+source/linux-hwe-edge/+bug/1661987

EDIT 2: This is definitely a software issue. Works fine with Windows and MAC with no additional tweaking on the same monitor. Here's the HDMI standard for USB-C to HDMI for those who care to read. http://www.hdmi.org/manufacturer/hdmialtmodeusbtypec.aspx

J. Doe
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  • it's something to do with the input type this isn't an issue with ubuntu this is a hardware issue HDMI to usb is non-standat and you need to do some electronics and saldering to make this work. check out the issue this guys gets only once he reboots into linux : https://youtu.be/rWmJ0RH_Feo?t=15m31s he fixes it by addapting his cable. your cable is different but I'm guessing it's a similar sort of issue. try to see if the issue exists under windows, if the strange colors persist under windows then I'm right it's not a software issue. – tatsu May 17 '17 at 07:54
  • this is not something that you can legitemately classify as a software issue even less ubuntu. any other linux distro would show the same behavior. and the fact it works under windows seems very fluke-y at this point. – tatsu May 22 '17 at 09:08
  • what? It's not flukey that it works with windows. It's flukey with ubuntu. I couldn't get it to work with any other distro. Didn't put a lot of effort though because Ubuntu is what i want to use. – J. Doe May 26 '17 at 07:45
  • that's what i said : E.G. it isn't an ubuntu issues since you get the same issue with other distros. I can't in good conscience rule out that the fact that it doesn't happen under windows is a fluke. in any case what you don't understand is that what you're doing (usb to HDMI) is non-standart and normally you need extra hardware (to bring extra voltage or a certain extra signal) for this to work. if windows provided a software solution to this hardware issue then that's on them not on us. you can't legitimately expect native USB to HDMI support do you not realize how ridiculous that sounds? – tatsu May 26 '17 at 11:14
  • I know that it works with Windows. Every time. That makes it a software issue. The standard already exists http://www.hdmi.org/manufacturer/HDMIAltModeUSBTypeC.aspx – J. Doe May 27 '17 at 18:50
  • I'm just trying to have you realize the realistic side to this here : no support's going to come for this not ever. If HDMI wasn't dead in the crib thanks to marketers it's soon to be dead now giving way to what should have always been where it stood : Display Port and usb-C is NOT a video-out you CAN convert HDMI to USB-C and I don't know why it is that you can (in my humble opinion it would be best if that were entirely impossible) and there's no reason why canonical or the linux community at large should bother implementing this. In the meantime if you're desperate to have this setup then – tatsu May 28 '17 at 09:27
  • do what I suggested in my very first reply : WELD. You need to alter the signal before it gets to the screen there's no real software solution to this unless you're capable of coding an intel graphics driver for linux that recognizes when the out is USB c and alters the signal accordingly. – tatsu May 28 '17 at 09:29
  • It's not non-standard thing, it's DisplayPort alt mode. Many phones support this connection type now. It's just DisplayPort output goes through the type C connector. – Alvin Liang Oct 25 '18 at 14:54
  • Bot bumped question and I see no answer, and that the hdmi.org link is dead. It appears the original question assumes that the USB-C cable is using HDMI alternate mode but this is unlikely. The HDMI alternate mode does not allow for simultaneous use of port for USB 3.x so if using an adapter with HDMI and USB 3.x ports then adapter is converting DisplayPort to HDMI. Using HDMI alt mode cable on a DisplayPort port is not going to result in any video, not even mangled video like that shown. – MacGuffin Oct 16 '22 at 01:20

1 Answers1

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I use a duel-boot ASUS with Intel HH graphics as well, i connect to a direct hdmi port in the laptop and receive no issue. sounds like a connector error rather than Ubuntu itself, if your laptop uses an hdmi port of its own try that, or

go into settings>displays>and click the one thats not built-in display,change the resolution after you put it on show on display 2 only, as the desktop resolution may be non-native to the tv/monitor.

Bailey Johnston
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