Sorry in advance for bad english and also for a noob question.

I have a problem with brightness on my tablet Supra M94BG. There is a system brightness slider, the range is 0% -- 100% (as usual), and the problem is that 0% corresponds 0 value in /sys/devices/platform/leds-mt65xx/leds/lcd-backlight/brightness , and 100% corresponds 90 value, and not 255, as expected. Manual setting of value in /sys/.../brightness to 255 gives really maximum level of brightness (as desired), but this value resets to 90 after screen is locked.

How can I correct the mapping?

1 Answer 1


Maybe everytime you unlock the screen, the phone sets the brightness to the current brightness value specified (set) by the slider.

This is something that has to be changed in the framework-res.apk .

If you know how to edit it using APKtool, just proceed.

Otherwise, the most easiest way is using a Tasker app.
Just add a task to set (echo) the brightness to 255 everytime screen is unlocked.

  • Thank you very much for letting me know about Tasker app, it is the best temporary solution for now! However, I think I still need to fix framework-res.apk so for this bug not to appear at all.
    – Vadik
    Commented Aug 16, 2015 at 20:04
  • 1
    And that's not a bug :) It's just to save your battery or avoid heating or something.
    – Gokul NC
    Commented Aug 17, 2015 at 13:10
  • As you have told me, I disassembled framework-res.apk and found these values there: <integer name="config_screenBrightnessSettingMinimum">30</integer> <integer name="config_screenBrightnessSettingMaximum">255</integer> <integer name="config_screenBrightnessSettingDefault">102</integer> No trace of maximum value of 90. Do I have to search in another place?
    – Vadik
    Commented Aug 17, 2015 at 21:23

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .