Linux-4.2.2 / 4.2.3 - ext4 dir_index / scheduler issue on ARM device(s) (no replies)

I'm using kernel 4.2.1 on all my devices without problems.
I decided to test newer kernels (4.2.2 / 4.2.3 ) but now the trouble starts.

First I noticed that I couldn't get files read from my samba share via mobile phone (es file manager)
no error message, just no files or directories are visible.
Same on my pc.
Accessing the files via ssh on the box(es) sometimes work, sometimes not.

http://pastebin.com/JSpTBKXW

This is happening sometimes when accessing the mounted root directory of the drives and mostly
The directory which raises this up contains 3366 directories, 31574 files (small audio files)

The filesystem is intact, it's working with kernel 4.2.1 and earlier and again with 4.3.0-rc1 and later
(4.3.0-rc6 atm on this box)

Because of this, I cannot update my other kirkwood devices

Any hints?

I could wait till kernel 4.3 is ready, shure.