Now install a custom rom for example Cloudy G3. Knock on still works so first you must double tap to wake the phone. Then tap in knock code to unlock, the lockscreen still shows. This is irritating as it's not default behaviour and add extras touches so it's like having a 5+ touch knock code.
So i installed stock rom again and the knock code is back to default. Root the stock rom and knock code is still default good. Install a custom recovery using autorec also installs a patched kernel as it is needed but the problem is it installs Cloudys kernel and knock code is back to the wrong behaviour. Double tap then enter knock code.
So afterwards i installed Bruces kernel and knock code is back to stock/default behaviour. Knock on from screen being totally off. But LED doesn't flash to indicate wrong knock code or screen turning on ha ha.
So i guess what i want is stock kernel patched to work with custom recovery in summary? Or just stick Bruces kernel onto any other rom i use. I don't want any fancy kernels with overclock features etc.
This is all my experience with an Int D802. I suppose it may be different depending on variant but i'm sure knock code used to work properly even with cloudys roms.