More details:

With a clean install of Ubuntu 12.04, upgraded to kernel 3.2.0-54, wireless does not work: error in dmesg "Failed to request firmware!"

From modinfo: required firmware:
firmware: rtlwifi/rtl8192cfwU_B.bin
firmware: rtlwifi/rtl8192cfwU.bin
firmware: rtlwifi/rtl8192cfw.bin

From Larry Finger I received the list of what is found in the kernel git repo for linux-firmware. While testing this, I noticed that rtl8192cfwU_B.bin and rtl8192cfwU.bin where missing and requested by the driver. Copying those two files from the Realtek website makes my wifi work again :-).

missing in the Ubuntu installation:
rtl8188efw  
rtl8188eufw
rtl8192cfwU_B
rtl8192cfwU
rtl8192cufw_A
rtl8192cufw_B
rtl8192cufw_TMSC

different:
rtl8192defw
rtl8192sefw
rtl8712u

the same:
rtl8192cfw
rtl8192cufw
rtl8723fw_B
rtl8723fw

Details of test machine:
test@test-Intel-powered-classmate-PC:/lib/firmware$ md5sum rtlwifi/*
748944fbffd3b08b5b1929bb6c7fc537 rtlwifi/rtl8192cfw.bin
943e9b714a926e630b8152d7aad91d2e rtlwifi/rtl8192cufw.bin
7a3b61dbd72e0efb22f892ece8020994 rtlwifi/rtl8192defw.bin
bccf9bf2276621770f101a60736b4004 rtlwifi/rtl8192sefw.bin
8e6396b5844a3e279ae8679555dec3f0 rtlwifi/rtl8712u.bin
ce50dfe07dbb1bfe9e14bdb315a4b28a rtlwifi/rtl8723fw_B.bin
69ccaffbe94cc0ef1b89c25290e19b2e rtlwifi/rtl8723fw.bin
test@test-Intel-powered-classmate-PC:/lib/firmware$ ls -l rtlwifi/
totaal 308
-rw-r--r-- 1 root root 13540 dec 11 2012 rtl8192cfw.bin
-rw-r--r-- 1 root root 16014 dec 11 2012 rtl8192cufw.bin
-rw-r--r-- 1 root root 20526 dec 11 2012 rtl8192defw.bin
-rw-r--r-- 1 root root 88856 dec 11 2012 rtl8192sefw.bin
-rw-r--r-- 1 root root 129304 dec 11 2012 rtl8712u.bin
-rwxr-xr-x 1 root root 22996 jul 11 14:43 rtl8723fw_B.bin
-rwxr-xr-x 1 root root 11662 jul 11 14:43 rtl8723fw.bin

test@test-Intel-powered-classmate-PC:/lib/firmware$ modinfo rtl8192ce
filename: /lib/modules/3.2.0-54-generic-pae/kernel/drivers/net/wireless/rtlwifi/rtl8192ce/rtl8192ce.ko
firmware: rtlwifi/rtl8192cfwU_B.bin
firmware: rtlwifi/rtl8192cfwU.bin
firmware: rtlwifi/rtl8192cfw.bin
description: Realtek 8192C/8188C 802.11n PCI wireless
license: GPL
author: Larry Finger	<email address hidden>
author: Realtek WlanFAE	<email address hidden>
author: lizhaoming	<email address hidden>
srcversion: DA52BF758B7683607AFCB85
alias: pci:v000010ECd00008176sv*sd*bc*sc*i*
alias: pci:v000010ECd00008177sv*sd*bc*sc*i*
alias: pci:v000010ECd00008178sv*sd*bc*sc*i*
alias: pci:v000010ECd00008191sv*sd*bc*sc*i*
depends: rtlwifi,rtl8192c-common,mac80211
intree: Y
vermagic: 3.2.0-54-generic-pae SMP mod_unload modversions 686 
parm: swenc:Set to 1 for software crypto (default 0)
 (bool)
parm: ips:Set to 0 to not use link power save (default 1)
 (bool)
parm: swlps:Set to 1 to use SW control power save (default 0)
 (bool)
parm: fwlps:Set to 1 to use FW control power save (default 1)
 (bool)
parm: debug:Set debug level (0-5) (default 0) (int)

*-network UNCLAIMED
                description: Network controller
                product: RTL8188CE 802.11b/g/n WiFi Adapter
                vendor: Realtek Semiconductor Co., Ltd.
                physical id: 0
                bus info: pci@0000:02:00.0
                version: 01
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress cap_list
                configuration: latency=0
                resources: ioport:2000(size=256) memory:80100000-80103fff