Dear Alpiners
I have installed Alpine 3.15.4 aarch64 on a Raspberry Pi 4 B rev 1.4, with
the intention to run Kodi. Other than the problem below with wifi, Alpine
is working really well with Kodi and it looks like a great fit for this
application.
I found that certain 5 GHz wifi channels are disabled in Alpine on the Pi.
Specifically, I need to be able to connect using channel 64, but this is
not possible with the channel disabled. 2.4 GHz wifi does work as expected.
I am in the UK and have country=GB set in wpa_supplicant.conf.
I decided to use sys mode for the Kodi Pi, although have duplicated the
problem in diskless install mode. I have also duplicated the issue with
32-bit armv7 Alpine.
This problem seems to be similar to the issue with 2.4 GHz channels 12-13
reported by Michal Artazov:
https://lists.alpinelinux.org/~alpine/users/%3CD5AC2D43-904F-4EE2-9FF0-DE0828D4AEF3%40signageos.io%3E
It also seems very similar to these problems reported in Manjaro and
EndeavourOS for Raspberry Pi 4:
https://forum.manjaro.org/t/raspberry-pi-4b-5ghz-upper-frequencies-disabled-tried-many-fixes/99155/1
https://forum.endeavouros.com/t/some-5-ghz-wifi-channels-are-disabled-in-raspberry-pi-4/24296
On Alpine Linux v3.15, I can see the following channels:
$ iwlist channel
lo no frequency information.
eth0 no frequency information.
wlan0 20 channels in total; available frequencies :
Channel 01 : 2.412 GHz
Channel 02 : 2.417 GHz
Channel 03 : 2.422 GHz
Channel 04 : 2.427 GHz
Channel 05 : 2.432 GHz
Channel 06 : 2.437 GHz
Channel 07 : 2.442 GHz
Channel 08 : 2.447 GHz
Channel 09 : 2.452 GHz
Channel 10 : 2.457 GHz
Channel 11 : 2.462 GHz
Channel 36 : 5.18 GHz
Channel 40 : 5.2 GHz
Channel 44 : 5.22 GHz
Channel 48 : 5.24 GHz
Channel 149 : 5.745 GHz
Channel 153 : 5.765 GHz
Channel 157 : 5.785 GHz
Channel 161 : 5.805 GHz
Channel 165 : 5.825 GHz
Current Frequency:2.412 GHz (Channel 1)
~ $ iw reg get
global
country GB: DFS-ETSI
(2400 - 2483 @ 40), (N/A, 20), (N/A)
(5150 - 5250 @ 80), (N/A, 23), (N/A), NO-OUTDOOR, AUTO-BW
(5250 - 5350 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS, AUTO-BW
(5470 - 5730 @ 160), (N/A, 26), (0 ms), DFS
(5725 - 5850 @ 80), (N/A, 23), (N/A), NO-OUTDOOR
(57000 - 71000 @ 2160), (N/A, 40), (N/A)
phy#0
country 99: DFS-UNSET
(2402 - 2482 @ 40), (6, 20), (N/A)
(2474 - 2494 @ 20), (6, 20), (N/A)
(5140 - 5360 @ 160), (6, 20), (N/A)
(5460 - 5860 @ 160), (6, 20), (N/A)
$ uname -a
Linux celestine.local 5.15.32-0-rpi4 #1-Alpine SMP PREEMPT Mon Mar 28 13:39:27 UTC 2022 aarch64 Linux
If I run Raspberry Pi OS (2022-04-04), based on Debian GNU/Linux 11
'bullseye' aarch64 on the same Pi, I see the following:
$ iwlist wlan0 channel
wlan0 32 channels in total; available frequencies :
Channel 01 : 2.412 GHz
Channel 02 : 2.417 GHz
Channel 03 : 2.422 GHz
Channel 04 : 2.427 GHz
Channel 05 : 2.432 GHz
Channel 06 : 2.437 GHz
Channel 07 : 2.442 GHz
Channel 08 : 2.447 GHz
Channel 09 : 2.452 GHz
Channel 10 : 2.457 GHz
Channel 11 : 2.462 GHz
Channel 12 : 2.467 GHz
Channel 13 : 2.472 GHz
Channel 34 : 5.17 GHz
Channel 36 : 5.18 GHz
Channel 38 : 5.19 GHz
Channel 40 : 5.2 GHz
Channel 42 : 5.21 GHz
Channel 44 : 5.22 GHz
Channel 46 : 5.23 GHz
Channel 48 : 5.24 GHz
Channel 52 : 5.26 GHz
Channel 56 : 5.28 GHz
Channel 60 : 5.3 GHz
Channel 64 : 5.32 GHz
Channel 100 : 5.5 GHz
Channel 104 : 5.52 GHz
Channel 108 : 5.54 GHz
Channel 112 : 5.56 GHz
Channel 116 : 5.58 GHz
Channel 120 : 5.6 GHz
Channel 124 : 5.62 GHz
Current Frequency:5.32 GHz (Channel 64)
$ iw reg get
global
country GB: DFS-ETSI
(2400 - 2483 @ 40), (N/A, 20), (N/A)
(5150 - 5250 @ 80), (N/A, 23), (N/A), NO-OUTDOOR, AUTO-BW
(5250 - 5350 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS, AUTO-BW
(5470 - 5725 @ 160), (N/A, 26), (0 ms), DFS
(5725 - 5875 @ 80), (N/A, 13), (N/A)
(57000 - 71000 @ 2160), (N/A, 40), (N/A)
phy#0
country 99: DFS-UNSET
(2402 - 2482 @ 40), (6, 20), (N/A)
(2474 - 2494 @ 20), (6, 20), (N/A)
(5140 - 5360 @ 160), (6, 20), (N/A)
(5460 - 5860 @ 160), (6, 20), (N/A)
$ uname -a
Linux raspberrypi 5.15.32-v8+ #1538 SMP PREEMPT Thu Mar 31 19:40:39 BST 2022 aarch64 GNU/Linux
With best wishes
Andrew