ubuntu-phone team mailing list archive

[Seth Forshee <seth.forshee@xxxxxxxxxxxxx>]

On Tue, Sep 03, 2013 at 12:27:02PM -0400, Tony Espy wrote:
> On 09/03/2013 12:21 PM, Alan Pope wrote:
> > On Tue, Sep 3, 2013 at 2:59 PM, Tony Espy <espy@xxxxxxxxxxxxx> wrote:
> >> Have you tried "iw reg" on your device?  Also, what device are you using?
> >>
> > 
> > FWIW I ran it on my Nexus 4..
> > 
> > root@ubuntu-phablet:/# iw reg get
> > country 00:
> > (2402 - 2472 @ 40), (6, 20)
> > (2457 - 2482 @ 20), (6, 20), PASSIVE-SCAN, NO-IBSS
> > (2474 - 2494 @ 20), (6, 20), NO-OFDM, PASSIVE-SCAN, NO-IBSS
> > (5170 - 5250 @ 40), (6, 20), PASSIVE-SCAN, NO-IBSS
> > (5735 - 5835 @ 40), (6, 20), PASSIVE-SCAN, NO-IBSS
> 
> It runs, I just haven't been entirely successful using it to the
> "change" the regdomain.

Fwiw, most of these driver implement a custom world domain, which means
that the default world domain (country 00, as above) does not get
applied to the device. The nexus 4 driver is no exception, except afaict
it tells the wireless core that it uses a custom world domain but never
informs the core about the rules for that domain. That should have the
effect of having the wireless core enforce absolutely no regulatory
rules on the device when the world domain is in effect.

There is a bunch of code in the driver though related to regulatory
stuff, so the driver seems to be bypassing the stock Linux regulatory
support in favor of its own stuff. This does seem to include a private
ioctl that can be used to set the country.

> Have you tried channel 13 on your device?  ;)-

'iw phy0 info' shows that channel 13 is supported and isn't disabled.
That's not surprising though since the driver doesn't use the core
regulatory support. But if I set up an AP on channel 13 it doesn't show
up in the scan results.

It seems very likely that there's some custom stuff going on in Android
to override the driver's default regulatory settings. I wouldn't be
surprised to discover that Android is using the private ioctl to change
the regulatory domain based on whatever location data it has available,
but that's just a wild guess.

Seth