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QT Application prevents Linux going to sleep on ARM9

  • Hi, I'm, writing Qt application that will run on 2.6 Linux on ARM9 board (i.MX28). And I ran into the problem: the OS doesn't go to sleep, if Qt application is running. Here is the log:

    root@HOST/opt$ ./digiflip -qws
    Could not read calibration: "/etc/pointercal"
    Initializing QFontEngineQPF failed for /lib/fonts/DejaVuSans.ttf
    Initializing QFontEngineQPF failed for /lib/fonts/DejaVuSans-Bold.ttf
    [ 481.990000] pswitch goto suspend
    [ 481.990000] PM: Syncing filesystems ...
    [ 482.040000] done.
    [ 482.050000] PM: Preparing system for standby sleep
    [ 482.050000] PM: pm_prepare_console

    It should look like this:
    root@HOST ~$ [ 292.410000] pswitch goto suspend
    [ 292.410000] PM: Syncing filesystems ...
    [ 292.450000] done.
    [ 292.450000] PM: Preparing system for standby sleep
    [ 292.450000] PM: pm_prepare_console
    [ 292.480000] PM: pm_notifier_call_chain
    [ 292.490000] PM: usermodehelper_disable
    [ 292.490000] PM: suspend_freeze_processes
    [ 292.500000] Freezing user space processes ... (elapsed 0.01 seconds) done.
    [ 292.520000] Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.

    Any suggestions on where to start debugging?

  • Hi mmaaxx,

    have you made the same test with a simple endless counting program in C/C++?
    Maybe the same problem occurs there too.

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