Qt Dice Example - 3D texture displays once only on Atom E3940 Linux

[mdear]

Hello,

I'm taking the "Dice" example (very nice) that deploys with Qt 6.6 and I managed to package it into a single-file AppImage deployment that I'm running on a Vartech embedded Linux device running an Intel Atom E3940 and Linux Mint Victoria (based on Ubuntu Jammy Jellyfish).

The first time, the app runs beautifully as expected. The touch screen responds, 3D zooms/pans/rotations are working.

Then, when I quit the app and re-run it, the textures don't appear to be wrapping around the 3D objects as I rotate them.

Any idea how to characterize this further and ultimately keep this from happening?

Is this a system issue or a coding issue do you think?

https://www.dropbox.com/scl/fi/74wore8dh86gjoyfiwfnl/2023-11-14-05.50.09.mov?rlkey=h87obsgscr6ayznu932ekyuk3&dl=0

Thanks !

[SGaist]

Hi,

Did you check the kernel messages ?
There might be some GPU related issues.

[mdear]

@SGaist Well, I did get these in my dmsg log, but I'm unsure what concrete actions I can take to resolve the issue.

The problem appears to be intermittent, which really means I'm not understanding the problem well enough.

After a fresh reboot of the device, the problem is seen:

[  171.632783] i915 0000:00:02.0: [drm] Resetting rcs0 for preemption time out
[  171.632872] i915 0000:00:02.0: [drm] QSGRenderThread[2286] context reset due to GPU hang
[  171.651466] i915 0000:00:02.0: [drm] GPU HANG: ecode 9:1:859ffffb, in QSGRenderThread [2286]

All ideas on how to characterize/work around/fix this are welcome ! I pretty much figured the GPU was hanging but the crazy thing is that I can actually run the app partially, it's just that the textures aren't seen. The dice actually roll about when I throw them in all cases.

Note: I'm also running the NoMachine server so I can interact with the device from another machine entirely (my screen is mirrored on my company laptop and I can see me interacting with the device as I move my mouse around, etc). Perhaps doing both things is too much for the GPU to handle.

I tried doing a systemctl stop nxserver and then rerunning the app but the GPU hang still happened.

[SGaist]

@mdear does it happen if you disable it before running the application at all ?

It might also be related to your GPU driver.

[mdear]

@SGaist I executed the command sudo apt-get install xserver-xorg-video-intel and I was informed I already had the latest i915 driver installed.

[SGaist]

@mdear sometimes the latest driver might be the issue 😅

You did not answer the question about the order of operations.

[mdear]

@SGaist Apologies for the delay. I disabled the remote access nxserver and was able to easily reproduce the issue using a directly-connected keyboard/mouse.

I approached Intel support but they dodged the question and asked me to pay for next level support so sadly it appears the Atom E3940 is not very Qt-friendly. We are looking into upgrade options to perhaps an i5-7300U.

[mdear]

@mdear I missed the questions from the Intel support engineer so I created a new issue to track : https://community.intel.com/t5/Graphics/GPU-lockup-still-being-seen-on-Atom-E3940-Linux-Mint-Victoria/m-p/1559135#M126797

[SGaist]

@mdear Thanks for the feedback !
That link seems to not be accessible.