We use the efusA9X board with CE7 and currently migrate to WEC2013. When setting the system power state to "ScreenOff", CE7 sets the backlight signal BL_CTRL (PWM backlight dimming) to constant low and VCFL_ON (backlight on) to low. In this case the display becomes dark as expected. Everything is fine so far.
The display mode is mode 9. We use only BL_CTRL, VCFL_ON is not connected.
For WEC2013 the behavior of the backlight PWM signal BL_CTRL seems to have been changed. In opposite to CE7 the level of BL_CTRL becomes constant HIGH in "ScreenOff" power state instead of LOW. Thus the display stays bright. (VCFL_ON changes to low, but - as mentioned - we do not use this signal).
ndcucfg's "backlight off/on" has no effect in WEC2013, dimming via changing the contrast works.
Is this change a bug or a feature?
Is it possible to change the behavior of BL_CTRL so that it is constant low as it was in CE7 instead of being high when in power state "ScreenOff"?
Is there a registry value, an ExtEscape sequence, a driver parameter or any other hack that allows to change this behavior?