WiFi: `iw reg set US` Has No Effect

I tried revisiting this issue yesterday, and still have the problem even with kernel 4.6.3. Manually installing the latest firmware image also didn't help. However, trying iw reg set US on a second laptop running the same kernel worked fine.

The problem machine is a Thinkpad X1 Carbon (Gen.3), which has an Intel 7265D WiFi card; the working machine is a Thinkpad T440p, which has an Intel 7260. I therefore conclude that there's a bug in the 7265D driver or firmware.

Workaround

I also discovered a workaround for the 7265D. Be aware this is a workaround, and may cause conflicts if/when an actual fix is released:

  • Remove all WiFi kernel drivers and dependent modules:
    sudo modprobe -r iwlmvm
  • Install the cfg80211 kernel module, using a kernel parameter to force the regulatory domain (in this case, 'US'):
    sudo modprobe cfg80211 ieee80211_regdom=US
  • Re-install the WiFi kernel drivers:
    sudo modprobe iwlmvm

You should now see the WiFi interface configured for the US (or whatever) regulatory domain:

$ iw reg get
country US: DFS-FCC
    (2402 - 2472 @ 40), (N/A, 30), (N/A)
    (5170 - 5250 @ 80), (N/A, 17), (N/A)
    (5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS
    (5490 - 5730 @ 160), (N/A, 23), (0 ms), DFS
    (5735 - 5835 @ 80), (N/A, 30), (N/A)
    (57240 - 63720 @ 2160), (N/A, 40), (N/A)

Update 2016.11.17: Fixed in Kernel 4.8 Series

I checked this issue again today for the first time after updating a couple weeks ago to a 4.8.x kernel, and discovered that the WiFi interface is now seems to be properly accepting the regulatory domain. This happened in or prior to kernel rev 4.8.5.

$ iw reg get
global
country 00: DFS-UNSET
    (2402 - 2472 @ 40), (6, 20), (N/A)
    (2457 - 2482 @ 20), (6, 20), (N/A), AUTO-BW, PASSIVE-SCAN
    (2474 - 2494 @ 20), (6, 20), (N/A), NO-OFDM, PASSIVE-SCAN
    (5170 - 5250 @ 80), (6, 20), (N/A), AUTO-BW, PASSIVE-SCAN
    (5250 - 5330 @ 80), (6, 20), (0 ms), DFS, AUTO-BW, PASSIVE-SCAN
    (5490 - 5730 @ 160), (6, 20), (0 ms), DFS, PASSIVE-SCAN
    (5735 - 5835 @ 80), (6, 20), (N/A), PASSIVE-SCAN
    (57240 - 63720 @ 2160), (N/A, 0), (N/A)

phy#0 (self-managed)
country US: DFS-UNSET
    (2402 - 2482 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ
    (5170 - 5250 @ 80), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
    (5250 - 5330 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
    (5490 - 5730 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
    (5735 - 5815 @ 80), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
    (5815 - 5835 @ 20), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN

After some code research I found out what the problem is:

The Intel WiFi device appears as a "self-manged" device, so the iw reg set won't be applied to it.

All you need to do is setting the iwlwifi parameter lar_disable=1:

  1. Either manually: modprobe -r iwlwifi & modprobe iwlwifi lar_disable=1
  2. Automatically: echo "options iwlwifi lar_disable=1" >/etc/modprobe.d/iwlwifi.conf

Tags:

Wifi

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