Display to Huawei VR Glasses

Is this issue ever happened if you don’t use that VR glass? I mean change to a common DP or HDMI monitors.

BTW, this log should be fine.

No, I have never seen this happen before. I have used a variety of HDMI and DP monitors, including other pairs of VR glasses including PiMax4k and Zeiss Cinimizers

What I am asking is
Are you saying that you can see gstreamer working or a blue background display with other DP or HDMI?

You can use other monitors to validate the steps first.

Sorry for the misunderstanding, I completed the test this morning and with a normal monitor (1920x1080p) it worked exactly as described and I got the expected display outputs.

So only the huawei VR glasses even not able to render anything after using those commands that are already verified on normal monitor?

Correct, the exact commands that worked for the normal HDMI monitor did not work for the VR Glasses.

Hi Ben,

What if you directly run the gstreamer pipeline along with the desktop? Will you see anything with that case?

I mean you don’t need to disable gdm or blank/unblank the monitor.

Also, if you don’t disable the gdm, will you see the desktop restore after blank/unblank?


Trying that definitely had some weird effects. When it was booted up with display in the glasses (it was corrupted) when I ran the GStreamer command I got no change in the display. I didn’t run any other commands from bootup.

After that when I had stopped the GStreamer command, I ran the command 1. “echo 4 > /sys/class/graphics/fb1/blank” and the display went blank as intedned but when I ran “echo 0 > /sys/class/graphics/fb1/blank”, it didn’t go back to normal. Just the backlight went on with nothing else displayed.

That weird effect should happen with no ubuntu desktop case. But that didn’t happen.

Please tell me

  1. When you see the “backlight went on, nothing else displayed case”, what would happen if you give below command, will you see blue background this time?

echo 0xffff0000 > /sys/kernel/debug/tegradc.1/background

  1. If you see nothing from (1), how about gstreamer command? Will you see anything under such circumstance? If still no output, could you share me the log from gstreamer?

  2. Could you also validate those steps as you do on HDMI but with DP this time to make sure you can see that on normal DP too?

When I repeated the same steps as before but tried to change the background, the background did change to blue, although it was still corrupted and had lines missing. When I ran the GStreamer command I didn’t get anything displayed. How do you get the log file from GStreamer?

When I repeated all the steps on a normal DP monitor (1080p) it worked exactly the same as the goggles just without the video corruption.

Here are the updated logs from the system while the goggles were displaying the desktop and it was corrupted.

clk_tree.txt (29.3 KB) mode.txt (236 Bytes) regs.txt (18.5 KB) stats.txt (34 Bytes) sor_regs.txt (6.0 KB)


Per checked the reg dump. We don’t see anything that have obvious error.

Thus, I would like to ask what did you mean in below comment? What was added here?

“If I then dial in some underscan in the NVIDIA X Server Settings app, the image fixes itself entirely.”

Any update here?

What I meant by that was there is a setting in the NVIDIA X Server configurator that is called underscan, when I increase the slider it make the image look better with less corruption.

Could you give the specific steps of how you set that?

I gave the exact steps in the very first post I made.

I have attached a screenshot of the application and it is a slider in the app

If you click on ‘Advanced’, and try to force composition pipeline or force full composition pipeline, or reduce viewPortOut or panning, does it improve ?

I also want to ask about the HP P240va screen here.

Do you always connect this monitor during all the test we’ve tried so far?

I have tried most of the tests with and without this screen. For the test without I have been using SSH to execute the commands.