Re: [PATCH 9/9] DFS: introduce radar_background parameter to config file

[Lorenzo Bianconi <lorenzo.bianconi@redhat.com>]

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On Mar 03, Jouni Malinen wrote:
> On Mon, Dec 20, 2021 at 04:48:24PM +0100, Lorenzo Bianconi wrote:
> > Introduce radar_background parameter to configuration file
> > in order to enable/disable background radar/CAC detection.
> 
> What's the use case for this new parameter and the configuration having
> to explicitly enable this functionality? Is there a reason for not doing
> this in cases where the driver supports this capability? It looks like
> patches 1..8 were enabling this functionality automatically and it is
> only this final patch that makes it depend on a configuration parameter
> (which is default by default).

I added this parameter just to add the capability to disable radar_background
even if the hw supports it (e.g. for testing/debugging). 

> 
> > diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
> > @@ -143,6 +143,13 @@ ssid=test
> > +# Enable radar/CAC detection through a dedicated background chain available on
> > +# some hw. The chain can't be used to transmits or receives frames.
> > +# This feature allows to avoid CAC downtime switching on a different channel
> > +# during CAC detection on the selected radar channel.
> > +# (default: 0 = disabled, 1 = enabled)
> > +#radar_background=0
> 
> How would someone writing hostapd configuration know when to enable
> this? Or maybe more importantly, when one should not enable this? Would
> use of that dedicated background chain result in some other capabilities
> getting reduced?

nope, the radar_chain is completely independent from the "data" ones.

> 
> This is also a bit unclear on what happens if the driver does not
> support this capability and radar_background=1 is explicitly set in the
> configuration.

it will not be enabled since we always check WPA_DRIVER_RADAR_BACKGROUND
capability.
Since it is not mandatory, I will drop this patch in the series and always
enable RADAR_BACKGROUND if supported by the hw.

Regards,
Lorenzo

> 
> -- 
> Jouni Malinen                                            PGP id EFC895FA
> 

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