[PATCH] wifi: mt76: mt7921: avoid undesired changes of the preset regulatory domain

[Mingyen Hsieh (謝明諺)]

On Fri, 2024-04-12 at 11:27 +0200, Nicolas Escande wrote:
>  	 
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>  On Fri Apr 12, 2024 at 10:53 AM CEST, Mingyen Hsieh wrote:
> > From: Leon Yen <leon.yen at mediatek.com>
> >
> > Some countries have strict RF restrictions where changing the
> regulatory
> > domain dynamically based on the connected AP is not acceptable.
> > This patch disables Beacon country IE hinting when a valid country
> code
> > is set from usersland (e.g., by system using iw or CRDA).
> 
> I always had trouble fully understanding the regulation but isn't the
> country
> code IE sole purpose to adapt the regulatory of the client ? 
> 
Hi Nicolas,

Yes, it is. However, if the users have set the specific country code
based on their region to the driver, they do not expect the country
setting to be changed by the country code IE as the AP cannot be
entirely trusted.

Best Regards,
Yen.

> >
> > Signed-off-by: Leon Yen <leon.yen at mediatek.com>
> > Signed-off-by: Ming Yen Hsieh <mingyen.hsieh at mediatek.com>
> > ---
> >  drivers/net/wireless/mediatek/mt76/mt7921/init.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/init.c
> b/drivers/net/wireless/mediatek/mt76/mt7921/init.c
> > index ef0c721d26e3..3c9a5fcd6924 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7921/init.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7921/init.c
> > @@ -135,6 +135,13 @@ mt7921_regd_notifier(struct wiphy *wiphy,
> >  dev->mt76.region = request->dfs_region;
> >  dev->country_ie_env = request->country_ie_env;
> >  
> > +if (request->initiator == NL80211_REGDOM_SET_BY_USER) {
> > +if (dev->mt76.alpha2[0] == '0' && dev->mt76.alpha2[1] == '0')
> > +wiphy->regulatory_flags &= ~REGULATORY_COUNTRY_IE_IGNORE;
> > +else
> > +wiphy->regulatory_flags |= REGULATORY_COUNTRY_IE_IGNORE;
> > +}
> > +
> >  if (pm->suspended)
> >  return;
> >  
>