DFS start_dfs_cac() failed, -1 / nl80211: Failed to start radar

[Zefir Kurtisi]

Hello Sahana,

as a follow up from what Michal already wrote: you need to ensure that the driver
is compiled with DFS support.

To double check, run 'iw phy0 info' and check for an output like this:
> valid interface combinations:
>   * #{ managed } <= 2048, #{ AP, mesh point } <= 8, #{ P2P-client, P2P-GO } <= 1, #{ IBSS } <= 1,
>     total <= 2048, #channels <= 1, STA/AP BI must match
>   * #{ WDS } <= 2048,
>     total <= 2048, #channels <= 1, STA/AP BI must match
>   * #{ IBSS, AP, mesh point } <= 1,
>     total <= 1, #channels <= 1, STA/AP BI must match, radar detect widths: { 20 MHz (no HT), 20 MHz, 40 MHz }

Ensure that there are valid radar detect widths.

Next step is to ensure that a DFS countrycode is selected (DFS channels in the
same output need to be tagged as 'usable').

Only then it becomes a hostapd issue and you should look carefully into the debug
log by running 'hostapd -ddt /var/run/hostapd-phy0.conf' and see if and how
hostapd reacts on the events received.


Good Luck,
Zefir


On 10/08/2015 02:39 PM, J Sahana wrote:
> Hi Michal,
> 
> I'm trying to run our application code on the same setup and facing issues with CAC. When RADAR_DETECT command is triggered to start CAC, I'm not getting any events from the driver.
> One thing that I'm suspecting is that driver may not be aware that DFS is enabled in the application code. In case of hostapd it was being read from the config file ieee80211h=1.
> So can you please let me know how to inform the driver that DFS is enabled in our application here? So that it can give the results of CAC. Or am I working in the wrong direction? Can you please provide some pointers?
> 
> Regards,
> Sahana
> 
> -----Original Message-----
> From: Zefir Kurtisi [mailto:zefir.kurtisi at neratec.com]
> Sent: Wednesday, October 07, 2015 3:10 PM
> To: J Sahana <J.Sahana at aricent.com>; Michal Kazior <michal.kazior at tieto.com>
> Cc: hostap at lists.shmoo.com
> Subject: Re: DFS start_dfs_cac() failed, -1 / nl80211: Failed to start radar
> 
> Ah ok, then never mind and sorry if I sounded rude.
> 
> Best,
> Zefir
> 
> On 10/07/2015 10:39 AM, J Sahana wrote:
>> Hi Zefir,
>>
>> I'm doing a reply all every time, but I'm not a registered user so the mailing list bounces back...that's why all the people in the mailing list are not getting the replies. Sorry for the inconvenience.
>>
>> Regards,
>> Sahana
>>
>> -----Original Message-----
>> From: Zefir Kurtisi [mailto:zefir.kurtisi at neratec.com]
>> Sent: Wednesday, October 07, 2015 2:07 PM
>> To: Michal Kazior <michal.kazior at tieto.com>; J Sahana
>> <J.Sahana at aricent.com>
>> Cc: hostap at lists.shmoo.com
>> Subject: Re: DFS start_dfs_cac() failed, -1 / nl80211: Failed to start
>> radar
>>
>> On 10/06/2015 03:38 PM, Michal Kazior wrote:
>>> On 6 October 2015 at 15:14, J Sahana <J.Sahana at aricent.com> wrote:
>>>> Hi Michal,
>>>>
>>>> [...]
>>>>
>>>>> -----Original Message----- From: Michal Kazior
>>>>> [mailto:michal.kazior at tieto.com] Sent: Tuesday, October 06, 2015
>>>>> 4:27 PM
>>>>> To: J Sahana <J.Sahana at aricent.com> Subject: Re: DFS
>>>>> start_dfs_cac() failed, -1 / nl80211: Failed to start radar
>>>>>
>>>>> [...]
>>>>>
>>>>> Avoid e-mailing me privately, please. Instead always go to the
>>>>> mailing list. It's much more productive because not only I, but
>>>>> many others, might be able to help you.
>>>>>
>>
>> Hello Sahana,
>>
>> you are ignoring Michal's kind request to handle this over the mailing list - either on purpose (which would render you impolite) or by mistake.
>>
>> In the latter case, please just hit 'Reply All' next time.
>>
>>
>> Regards,
>> Zefir
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>>
> 
> "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."
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