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AM335x poor graphics performance in SDK 2.x

I am running a QML-based Qt5 application on a VAR-SOM-AM33 board and seeing a significant decrease in UI performance after migrating to Processor SDK version 2.00.01 (Yocto Fido build) from version 1.9.0.12 (Yocto Daisy build). In particular, animations and page transitions which were previously fluid are now extremely slow. I am also seeing a kernel panic upon exiting my application: http://pastebin.com/gpH5KYAA. I found a previous forum post with the same trace, but no one has posted a solution: https://e2e.ti.com/support/arm/sitara_arm/f/791/t/472074. I am not 100% positive the kernel panic is related to the poor performance, but it seems likely.

As part of the Yocto upgrade, Qt also got upgraded from version 5.4.1 to 5.5, which I believe had some major changes in the QML engine; however, those changes were supposed to make QML more performant, not less, so I don't think that is likely the cause, but I wanted to mention it anyway.

My /etc/powervr.ini looks like this:

[default]
WindowSystem=libpvrDRMWSEGL_FRONT.so
DisableHWTQTextureUpload=1
DefaultPixelFormat=RGB565

Am I missing something here? Perhaps there is a configuration that I have overlooked? Or is the slow performance simply the nature of the DRM window system in 2.x vs. the previously used FBdev which writes directly to the framebuffer? I would like to keep up with the latest SDK version in my products, but I am having second thoughts about it now that I am having these issues. Surely others have noticed this after migrating to 2.x? Any advice would be appreciated.  If you need more info, please let me know what you need and I will be happy to provide it.

  • I will ask the software team to comment.
  • Hi,

    I haven't noticed such behavior on the boards I have (AM335x Starter Kit & Beaglebone Black).

    Is it possible to test your QT app on any of the reference ti designs (AM335x GP EVM or AM335x Starter Kit) to see if you will replicate the behaviour of your VAR-SOM-AM33?

    Best Regards,
    Yordan
  • Hi Yordan. Thanks for your reply. We went ahead and ordered a starter kit but it may be a while before we are able to test it. Is there anything else we can try on our board in the meantime? Are there other diagnostics or tools that would give you more information?
  • JacobeKenobi said:
    Or is the slow performance simply the nature of the DRM window system in 2.x vs. the previously used FBdev which writes directly to the framebuffer?

    Just to clarify: DRM is not a window system, it solely provides direct framebuffer access (just like fbdev, but in a more flexible and modern way).

  • I have the same issue with Yocto v2.1 based on TI SDK 3.01.

    I have made a little vedio to demonstrate the effect: www.youtube.com/watch

    Note how mouse pointer is moving smoothly on the blank area of the window and lags over at controls. It's as if it is going through jelly. If you have more controls on the window, mouse becomes so laggy, it's unusable. CPU load is minimal though.

    There could be no error in the example app in the vedio - we created a blank QT Widget project, put the controls on the form and that's it, it is not doing anything else at all.

    Has anyone seen such mouse issues?