ath9k DFS failed -16 (Device or resource busy)

[Janusz Dziedzic]

On 20 February 2016 at 18:24, Benoit <benoitne at gmail.com> wrote:
> Hi,
>
> I am trying to run my AP on 5Ghz but I have some issue..
> First of all I changed my country code thanks to CRDA to FR.
>
> iw reg get
> global
> country FR: DFS-ETSI
>     (2402 - 2482 @ 40), (N/A, 20), (N/A)
>     (5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
>     (5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
>     (5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS
>     (57000 - 66000 @ 2160), (N/A, 40), (N/A)
>
> iw list
>     Frequencies:
>             * 5180 MHz [36] (15.0 dBm) (no IR)
>             * 5200 MHz [40] (15.0 dBm) (no IR)
>             * 5220 MHz [44] (15.0 dBm) (no IR)
>             * 5240 MHz [48] (16.0 dBm) (no IR)
>             * 5260 MHz [52] (15.0 dBm) (no IR, radar detection)
>               DFS state: usable (for 924 sec)
>               DFS CAC time: 60000 ms
>             * 5280 MHz [56] (15.0 dBm) (no IR, radar detection)
>               DFS state: usable (for 924 sec)
>               DFS CAC time: 60000 ms
>             * 5300 MHz [60] (15.0 dBm) (no IR, radar detection)
>               DFS state: usable (for 924 sec)
>               DFS CAC time: 60000 ms
>             * 5320 MHz [64] (15.0 dBm) (no IR, radar detection)
>               DFS state: usable (for 924 sec)
>               DFS CAC time: 60000 ms
>             * 5500 MHz [100] (17.0 dBm) (no IR, radar detection)
>               DFS state: usable (for 924 sec)
>               DFS CAC time: 60000 ms
>             * 5520 MHz [104] (17.0 dBm) (no IR, radar detection)
>               DFS state: usable (for 924 sec)
>
> so I should be able to use channels 100-104 if I activate DFS, but I have an
> issue when I start hostap :
> HT40: control channel: 104  secondary channel: 100
> Completing interface initialization
> Mode: IEEE 802.11a  Channel: 104  Frequency: 5520 MHz
> DFS 2 channels required radar detection
> DFS all channels available, (SKIP CAC): no
> DFS 0 chans unavailable - choose other channel: no
> pnic_wlan: interface state HT_SCAN->DFS
> DFS start CAC on 5520 MHz
> pnic_wlan: DFS-CAC-START freq=5520 chan=104 sec_chan=-1, width=0, seg0=0,
> seg1=0, cac_time=60s
> nl80211: Start radar detection (CAC) 5520 MHz (ht_enabled=1, vht_enabled=0,
> bandwidth=40 MHz, cf1=5510 MHz, cf2=0 MHz)
>   * freq=5520
>   * vht_enabled=0
>   * ht_enabled=1
>   * sec_channel_offset=-1
>   * channel_type=2
> nl80211: Failed to start radar detection: -16 (Device or resource busy)
> DFS start_dfs_cac() failed, -1
> Interface initialization failed
>
> I tried to compile my kernel module with the modified module but I only
> found one value (|ATH9K_DFS_CERTIFIED) but it doesn't change anything I keep
> having the same error message in hostap.
>
What show:
iw phyX info |grep radar?

I have:
radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz }

What in your case?
Maybe you don't have patch for HT40?
Does DFS HT20 works correctly?

BR
Janusz

> Just trying my luck here if anyone has some idea for me..
> many thanks
> |
>
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