Nominate our 2022 Qt Champions!

[SOLVED] Slow framebuffer with Qt5

  • Hi everyone,
    I switched from Qt4.8 to Qt5.1.1 for my application. Unfortunately I do not yet have EGL support working on my target, so I am using the linuxfb plugin. But this to slow; if I change the screen, I see how it is built from top to bottom. It was ok under Qt4.

    So my question is:
    Do I miss something, do I have an error or is it just that way?

    The target is an arm am3354 with Linux on it.
    Thanks for any advice or hints.

  • Hi ufas,

    were you able to make it through your issue with the am3354 chip and Qt 5.1?

  • No, unfortunately not. It is not the highest priority task, but will remain on the task list.

    Meanwhile I have seen that the linuxfb is not really usable; sometimes the screen is not redrawn when it should be (for example after closing a modal dialog).

    We try to get EGL to work as it seems to be to Qt way (since we use Yocto and using EGL without X11 seems to be not really tested it is not yet working that way either; but thats a different problem).

  • We use now a new Kernel (3.14) and with that also the tilcdc driver instead of the da8xx driver.
    It is much better now. Swiping images is smooth, still with high CPU load, but good enough.

Log in to reply