I recently got a Toshiba Satellite L875-S7208 with Windows 7 preinstalled. I installed Ubuntu 12.04 LTS dual boot to the same Windows partition.

However, usually 15 minutes or less after booting, the wifi connection dies.

Here's some hopefully relevant information:

lspci -knn

00:00.0 Host bridge [0600]: Intel Corporation 2nd Generation Core Processor Family DRAM Controller [8086:0104] (rev 09)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel driver in use: agpgart-intel
00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09)
    Subsystem: Toshiba America Info Systems Device [1179:fb40]
    Kernel driver in use: i915
    Kernel modules: i915
00:14.0 USB controller [0c03]: Intel Corporation Panther Point USB xHCI Host Controller [8086:1e31] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel driver in use: xhci_hcd
00:16.0 Communication controller [0780]: Intel Corporation Panther Point MEI Controller #1 [8086:1e3a] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel driver in use: mei
    Kernel modules: mei
00:1a.0 USB controller [0c03]: Intel Corporation Panther Point USB Enhanced Host Controller #2 [8086:1e2d] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel driver in use: ehci_hcd
00:1b.0 Audio device [0403]: Intel Corporation Panther Point High Definition Audio Controller [8086:1e20] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb40]
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd-hda-intel
00:1c.0 PCI bridge [0604]: Intel Corporation Panther Point PCI Express Root Port 1 [8086:1e10] (rev c4)
    Kernel driver in use: pcieport
    Kernel modules: shpchp
00:1c.1 PCI bridge [0604]: Intel Corporation Panther Point PCI Express Root Port 2 [8086:1e12] (rev c4)
    Kernel driver in use: pcieport
    Kernel modules: shpchp
00:1c.2 PCI bridge [0604]: Intel Corporation Panther Point PCI Express Root Port 3 [8086:1e14] (rev c4)
    Kernel driver in use: pcieport
    Kernel modules: shpchp
00:1d.0 USB controller [0c03]: Intel Corporation Panther Point USB Enhanced Host Controller #1 [8086:1e26] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel driver in use: ehci_hcd
00:1f.0 ISA bridge [0601]: Intel Corporation Panther Point LPC Controller [8086:1e59] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel modules: iTCO_wdt
00:1f.2 SATA controller [0106]: Intel Corporation Panther Point 6 port SATA Controller [AHCI mode] [8086:1e03] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel driver in use: ahci
00:1f.3 SMBus [0c05]: Intel Corporation Panther Point SMBus Controller [8086:1e22] (rev 04)
    Subsystem: Toshiba America Info Systems Device [1179:fb41]
    Kernel modules: i2c-i801
02:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter [10ec:8176] (rev 01)
    Subsystem: Realtek Semiconductor Co., Ltd. Device [10ec:8211]
    Kernel driver in use: rtl8192ce
    Kernel modules: rtl8192ce
03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 05)
    Subsystem: Toshiba America Info Systems Device [1179:fb37]
    Kernel driver in use: r8169
    Kernel modules: r8169

lsmod

Module                  Size  Used by
snd_hda_codec_hdmi     32474  1 
snd_hda_codec_realtek   224066  1 
joydev                 17693  0 
rfcomm                 47604  0 
bnep                   18281  2 
bluetooth             180104  10 rfcomm,bnep
parport_pc             32866  0 
ppdev                  17113  0 
arc4                   12529  2 
snd_hda_intel          33773  3 
snd_hda_codec         127706  3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel
snd_hwdep              13668  1 snd_hda_codec
snd_pcm                97188  3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_seq_midi           13324  0 
snd_rawmidi            30748  1 snd_seq_midi
snd_seq_midi_event     14899  1 snd_seq_midi
snd_seq                61896  2 snd_seq_midi,snd_seq_midi_event
snd_timer              29990  2 snd_pcm,snd_seq
snd_seq_device         14540  3 snd_seq_midi,snd_rawmidi,snd_seq
psmouse                87692  0 
serio_raw              13211  0 
rtl8192ce              84826  0 
rtl8192c_common        75767  1 rtl8192ce
rtlwifi               111202  1 rtl8192ce
mac80211              506816  3 rtl8192ce,rtl8192c_common,rtlwifi
snd                    78855  16 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
sparse_keymap          13890  0 
uvcvideo               72627  0 
videodev               98259  1 uvcvideo
v4l2_compat_ioctl32    17128  1 videodev
mac_hid                13253  0 
mei                    41616  0 
wmi                    19256  0 
soundcore              15091  1 snd
i915                  472941  3 
snd_page_alloc         18529  2 snd_hda_intel,snd_pcm
drm_kms_helper         46978  1 i915
cfg80211              205544  2 rtlwifi,mac80211
drm                   242038  4 i915,drm_kms_helper
i2c_algo_bit           13423  1 i915
video                  19596  1 i915
lp                     17799  0 
parport                46562  3 parport_pc,ppdev,lp
r8169                  62099  0 
ums_realtek            18248  0 
uas                    18180  0 
usb_storage            49198  1 ums_realtek

dmesg | grep firmware

[   15.692951] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[   16.240881] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  452.419288] rtl8192c_common:rtl92c_firmware_selfreset(): 8051 reset fail.
[  458.572211] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  465.440640] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  472.337617] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  479.175471] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  485.978582] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  492.764893] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  499.579348] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  506.386934] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  513.209545] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  519.991365] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  526.778375] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  533.629695] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  540.426004] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  547.238125] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  554.024434] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  560.854794] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  567.678160] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  574.494666] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  581.336653] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  588.157710] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  595.221122] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  602.047429] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  608.829534] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  615.639079] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  622.454991] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  629.273231] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  636.056613] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  642.858096] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  649.640753] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  657.184094] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  664.008018] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  670.838639] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  677.675418] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  684.507255] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  691.310994] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  698.095325] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  704.914509] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin
[  711.725178] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cfw.bin

uname -r

3.2.0-29-generic

ifconfig

eth0      Link encap:Ethernet  HWaddr 4c:72:b9:59:6c:61  
      inet addr:192.168.0.11  Bcast:192.168.0.255  Mask:255.255.255.0
      inet6 addr: fe80::4e72:b9ff:fe59:6c61/64 Scope:Link
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:4447 errors:0 dropped:0 overruns:0 frame:0
      TX packets:2762 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000 
      RX bytes:3671147 (3.6 MB)  TX bytes:335133 (335.1 KB)
      Interrupt:42 Base address:0x2000 

lo        Link encap:Local Loopback  
      inet addr:127.0.0.1  Mask:255.0.0.0
      inet6 addr: ::1/128 Scope:Host
      UP LOOPBACK RUNNING  MTU:16436  Metric:1
      RX packets:515 errors:0 dropped:0 overruns:0 frame:0
      TX packets:515 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:0 
      RX bytes:83153 (83.1 KB)  TX bytes:83153 (83.1 KB)

wlan0     Link encap:Ethernet  HWaddr 74:e5:43:32:47:95  
      UP BROADCAST MULTICAST  MTU:1500  Metric:1
      RX packets:280 errors:0 dropped:0 overruns:0 frame:0
      TX packets:51 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000 
      RX bytes:32958 (32.9 KB)  TX bytes:10431 (10.4 KB)