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

[Zefir Kurtisi]

On 10/08/2015 03:06 PM, J Sahana wrote:
> Hi Zefir,
> 
> Hostapd works totally fine in my setup. I have another application which is
> similar to hostapd on which I'm working. I wanted to know if the driver needs
> to be informed about DFS being enabled in the application before triggering
> commands like RADAR_DETECT. I don?t know how this is done in hostapd. Can you
> please help.
> 
> Regards, Sahana
> 

Ah, that's a different story then. In that case I assume you have read and a good
understanding of the files src/drivers/driver_nl80211.c and src/ap/dfs.c

>From my understanding, the only command to the driver is NL80211_CMD_RADAR_DETECT
to initiate a CAC on current channel (after you set up the interface, but before
you start beaconing). In response, you will receive events
EVENT_DFS_{RADAR_DETECTED | CAC_FINISHED | CAC_ABORTED | NOP_FINISHED} which you
need to handle accordingly (start beaconing, process CSA, don't use channel while
in NOP, etc.).

Essentially, if NL80211_CMD_RADAR_DETECT succeeds, you're all set, if it fails,
you need to dig driver following the error code.


Good Luck,
Zefir