Wifi regression on 16.04 Centrino Wireless-N 1000

Since I updated my Acer 1810TZ laptop to 16.04 WIFI is unstable.

Intel Centrino Wireless-N 1000.

dmesg | grep iwlwifi
[    4.897866] iwlwifi 0000:02:00.0: can't disable ASPM; OS doesn't have ASPM control
[    4.904631] iwlwifi 0000:02:00.0: loaded firmware version 39.31.5.1 build 35138 op_mode iwldvm
[    4.960067] iwlwifi 0000:02:00.0: CONFIG_IWLWIFI_DEBUG disabled
[    4.960074] iwlwifi 0000:02:00.0: CONFIG_IWLWIFI_DEBUGFS enabled
[    4.960078] iwlwifi 0000:02:00.0: CONFIG_IWLWIFI_DEVICE_TRACING enabled
[    4.960083] iwlwifi 0000:02:00.0: Detected Intel(R) Centrino(R) Wireless-N 1000 BGN, REV=0x6C
[    4.962373] iwlwifi 0000:02:00.0: L1 Enabled - LTR Disabled

I had bad WIFI performance in the past but in 15.10 it was working perfectly.

I have this in the dmesg:

7639.025981] wlan0: deauthenticating from 64:66:b3:4f:eb:5d by local choice (Reason: 3=DEAUTH_LEAVING)
[ 7639.160055] cfg80211: World regulatory domain updated:
[ 7639.160062] cfg80211:  DFS Master region: unset

I read some tips to disable power settings sudo iwconfig wlan0 power off, but that doesn't make much difference now. Any ideas to improve it? Can I use different firmware or how to debug?

Solution 1:

WIFI current regulatory domain

It seems my WIFI country code for the Kernels current regulatory domain wasn't set.

Update that and reboot:

sudo nano /etc/default/crda

REGDOMAIN=UK

New upstream kernel

Probably more important, I also tried a new upstream kernel

I saw WIFI bug-reports that were fixed with a new kernel. Read more about upstream kernels here.

Download and install the packages that corresponds to your architecture (e.g. AMD64, kernel 4.6-rc7-wily)

linux-headers-4.6.0-040600rc7-generic_4.6.0-040600rc7.201605081830_amd64.deb
linux-headers-4.6.0-040600rc7_4.6.0-040600rc7.201605081830_all.deb
linux-image-4.6.0-040600rc7-generic_4.6.0-040600rc7.201605081830_amd64.deb


sudo dpkg -i *.deb
sudo reboot

It seems to have solved my problem.