Need help i'm having the boot loop with KitKat kernels .I told about this issue to Sultan XDA ..and he replied as
Tell those kernel devs to fix their keypad driver:
[ 109.012786] Unable to handle kernel NULL pointer dereference at virtual address 0000001c
[ 109.012969] pgd = d5f14000
[ 109.013061] [0000001c] *pgd=5594e831, *pte=00000000, *ppte=00000000
[ 109.013458] Internal error: Oops: 17 [#1] PREEMPT SMP
[ 109.013580] Modules linked in: dhd vibrator frandom
[ 109.013977] CPU: 1 Not tainted (3.0.101-stock++ #1)
[ 109.014099] PC is at sec_keypad_enable_show+0x10/0x24.
[ 109.014282] LR is at dev_attr_show+0x1c/0x48...so find my problem here:
http://xdaforums.com/galaxy-s2-tmobile/help/help-boot-4-3-roms-t2999362/post58093351#post58093351
I askes for a fix and he replied :
Your keypad hardware is slow to initialize at boot:
[ * *1.250640] [TKEY] get_touchkey_firmware F/W version: 0x0, Module version:0x0
[ * *1.250762] f/w read fail retry 6
[ * *1.250946] EXT_I2C No ACK
So some of the data structs in the keypad driver remain in a null state until keypad probe can complete. Some of that data is accessed before keypad probe on your specific device can finish (so it is dereferencing null data), thus crashing the kernel. It's being caused by the keypad-disabler feature, which my kernel does not have. Sorry, but I'm not really interested in fixing other people's kernels, so I can't help you with that..... Can u fix this for me plzz!!