While testing Kernel 3.18.0-rc5 and -rc4 I discovered that I am unable to connect to my AP with my built-in RTL8188CE wifi chip. However, it works in Kernel 3.17.3 stable.

dmesg does not hold much output regarding wifi:
[    0.254796] cfg80211: Calling CRDA to update world regulatory domain
[    6.689429] rtl8192ce:_rtl92ce_read_chip_version():<0-0> Chip Version ID: B_CHIP_88C
[    6.700929] rtl8192ce: Using firmware rtlwifi/rtl8192cfw.bin
[    6.701416] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
[    6.701978] rtlwifi: rtlwifi: wireless switch is on
[   21.558934] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   72.470712] rtl8192ce:rtl92ce_get_hw_reg():<0-0> switch case not processed

On ifup the line
  IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
is appended, while on ifdown it reads
  rtl8192ce:rtl92ce_get_hw_reg():<0-0> switch case not processed

I looked for the value of the parameter "variable" which is passed to the function rtl92ce_get_hw_reg regarding the uncovered switch case. It is 92, which seems to be HAL_DEF_WOWLAN. I have no idea if this is related to the actual connectivity problem, but the working driver in 3.17.3 does not output the dmesg line.

I tried to track down the change which causes the driver to break using git bisect:
  commit 38506ecefab911785d5e1aa5889f6eeb462e0954
  Author: Larry Finger <Larry.Finger@lwfinger.net>
  Date:   Mon Sep 22 09:39:19 2014 -0500

      rtlwifi: rtl_pci: Start modification for new drivers
    
      Future patches will move the drivers for RTL8192EE and RTL8821AE
      from staging to the regular wireless tree. Here, the necessary features
      are added to the PCI driver. Other files are touched due to changes
      in the various data structs.
    
      Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
      Signed-off-by: John W. Linville <linville@tuxdriver.com>