ANNOUNCE:
New testing kernel available.

The last testing kernel caused reboots probably because it had some experimental debugging code to try to catch the bad driver which crashed kthread sometimes, and such code probably ended causing more problems when the bug triggered.
The openwrt kernel patches have inspired me to make some minor changes related to preemption and irq locking in the touchscreen and retu drivers, which are among the suspicious of causing the kthread crash. Those changes are completely safe, and in the worst case, won't do anything, but in the best case the kthread crash may be fixed.

So, this new testing kernel has the patch to fix the shutdown issue, and the newly patched drivers.
I'm running it right now and it is completely safe, the worst that can happen is that kthread crashes once about a week to some months. But if you guys expect me to do all the testing, it'll be months again before I can take a decision. If the new patches have a positive impact, it can take even longer, just think, if one of those drivers caused the crash and now it is fixed, but it isn't the only one driver causing the crash.. it will take much longer to crash.
A symptom of the kthread crash is that the hardware keys stop working.

PLEASE INSTALL THIS KERNEL AND REPORT UPTIME AND CRASHES (IF ANY)