Comment 6 for bug 1379524

I have exactly the same issue on my HP Pavilion 15-p163nr.

Issue: weak signal, frequent disconnects.
Kubuntu 14.04 LTS
Uname both: Linux 3.13.0-37-generic x86_64 and Uname: Linux 3.13.0-39-generic x86_64

And I did the same thing before I found this thread — build the driver from source found at http://www.broadcom.com/support/802.11/linux_sta.php and install it.
After that the signal is much better — but still after some time it loses the connectivity (without any apparent indication — i.e. 3 bars in notification icon but websites load forever.
In my attempt to fix that I did the following:
1. Set IPv6 in my connection settings to Ignore
2. Enforce the regulatory domain to my country code (from dmesg it seemed that regulatory domain was periodically switching from 'world' to 'Ru'):
sudo sed -i 's/^REG.*=$/&RU/' /etc/default/crda
sudo iw reg set RU
3. (Just in case):
sudo update-initramfs -u

And it seems to work almost fine now.

I also tried 14.10 and had issues with wifi too — the signal was OK but it constantly disconnected and even to the point where my aweful DLink Dir-300 had to be restarted — connection was repeatedly lost on my other devices too.

PS. Hendrik, as far as I understand the 5 Ghz frequency is not supported by the controller itself (at least for Pavilion 15-p163nr).

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$ lspci -vnn -d 14e4:
08:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)
        Subsystem: Hewlett-Packard Company Device [103c:2230]
        Flags: bus master, fast devsel, latency 0, IRQ 18
        Memory at b5500000 (64-bit, non-prefetchable) [size=32K]
        Capabilities: <access denied>
        Kernel driver in use: wl
______________________
$ lsmod | grep "brcmsmac\|ssb\|wl\|b43\|bcma"
wl 6363686 0
cfg80211 484040 1 wl
______________________
That's what I'm having now in:

$ dmesg | grep wl
[ 11.946547] wl: module license 'unspecified' taints kernel.
[ 11.949084] wl: module verification failed: signature and/or required key missing - tainting kernel
[ 8974.077536] Modules linked in: pci_stub vboxpci(OX) vboxnetadp(OX) vboxnetflt(OX) vboxdrv(OX) bnep rfcomm uvcvideo videobuf2_vmalloc videobuf2_memops btusb videobuf2_core bluetooth videodev hp_wmi sparse_keymap snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm crct10dif_pclmul crc32_pclmul snd_hda_codec_realtek ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd snd_hda_intel snd_hda_codec snd_hwdep joydev snd_pcm serio_raw snd_page_alloc snd_seq_midi snd_seq_midi_event lpc_ich snd_rawmidi wl(POX) snd_seq snd_seq_device rtsx_pci_ms cfg80211 snd_timer snd memstick mei_me mei soundcore hp_accel lis3lv02d hp_wireless input_polldev intel_smartconnect mac_hid parport_pc ppdev lp parport rtsx_pci_sdmmc nouveau i915 psmouse mxm_wmi ttm ahci i2c_algo_bit libahci drm_kms_helper r8169 drm mii rtsx_pci wmi video
[ 8974.077637] CPU: 0 PID: 441 Comm: wl_event_handle Tainted: P OX 3.13.0-39-generic #66-Ubuntu
[ 8974.077847] [<ffffffffa05a9f3b>] wl_notify_roaming_status+0xcb/0x150 [wl]
[ 8974.077942] [<ffffffffa05a8b72>] wl_event_handler+0x62/0x220 [wl]
[ 8974.078014] [<ffffffffa05a8b10>] ? wl_cfg80211_resume+0x440/0x440 [wl]

Let me know if any details from me could help.