Re: [PATCH 01/13] wifi: cfg80211: Add provision to advertise multiple radio in one wiphy

Nicolas Escande
2024-04-12T07:39:08Z

On Fri Apr 12, 2024 at 5:50 AM CEST, Vasanthakumar Thiagarajan wrote:
>
>
> On 4/11/2024 10:09 PM, Maxime Bizon wrote:
> >
> > On Thu, 2024-04-11 at 21:56 +0530, Vasanthakumar Thiagarajan wrote:
> >
> > Hello,
> >
> > Thanks for making it clear,
> >
> >
> >>> For example, starting a 5Ghz AP in ax-only mode, and at the same
> >>> time
> >>> creating a STA interface on 2.4GHz ?
> >
> >> Yes, such use cases continue to be supported in single wiphy mode.
> >
> > Understood, but I see some corner cases.
> >
> >
> > For example, assume two bands AP hardware, 2.4GHz and 5GHz.
> >
> > Previously:
> > - phy0 is 2.4Ghz
> > - phy1 is 5Ghz
> > - iw phy phy0 interface create wlan0 type managed
> > - iw dev wlan0 scan
> >
> > => will only scan 2.4Ghz
> >
> >
> > With single phy approach:
> > - phy0 is 2.4Ghz + 5Ghz concurrent
> > - # iw phy phy0 interface create wlan0 type managed
> > - # iw dev wlan0 scan
> >
> > => will scan both bands ?
> >
>
> Yes, both the bands will be scanned if freq list is not given
>
> > - <starting from previous state>
> > - # iw phy phy0 interface create wlan1 type __ap
> > - # hostapd -i wlan1 <config>
> > - # iw dev wlan0 scan
> >
> > => what will happen then ?
> >
>
> Scan will be carried out on all the radios including the one on which AP interface is
> running. Scan with freq list can be used not to disturb the radio of AP interface.
>
> > > Same goes for hostapd ACS, I assume specifying freqlist becomes
> > mandatory or we can't predict which band the AP will be on ?
> >
>
> If no freq list is given, ACS will run through all the bands and select a channel from any
> of the bands. But this can be optimized to do ACS and channels selection on a particular
> band using channellist/freqlist hostapd configurations.
Hello,

And in a (very unlikely) case that there are two underlying radios that can
operate on the same frequencies, how would freqlist enable us to really select
the underlying radio ?

Thanks
>
> Vasanth