[ I'll preface this by saying that the more I look at the regulatory
core, the more I realize I'm confused or wrong at times. So forgive me
if I've made errors along the way, and please do correct me. ]
On Tue, Mar 24, 2020 at 8:11 PM Andy Huang <tehuang@xxxxxxxxxxx> wrote:
> > On Tue, Mar 24, 2020 at 03:52:15PM +0800, yhchuang@xxxxxxxxxxx wrote:
> > > --- a/drivers/net/wireless/realtek/rtw88/Kconfig
> > > +++ b/drivers/net/wireless/realtek/rtw88/Kconfig
> > I'm still not sure why rtw88 needs this, and nobody else does. I read
>
> I think in Atheros driver, ATH_REG_DYNAMIC_USER_REG_HINTS config serves
> the same purpose.
Ah, I forgot about that one, sorry.
> > your commit message, but that doesn't sound like something that belongs
> > in a single driver still.
> >
>
> As our previous commit message claims, it is due to FCC [...]
Yes, I saw that: my point was that effectively all drivers are subject
to this FCC rule, and so this could be a common CONFIG_*. But if we
already have the ATH_* one (I missed that, above), I guess we can have
an rtw88 one too. It might be less confusing (and more
straightforwardly-implemented) if we moved this stuff to the core
someday, though.
> > > + ret = regulatory_hint(hw->wiphy, rtwdev->efuse.country_code);
> > > + if (ret)
> > > + rtw_warn(rtwdev, "failed to hint regulatory: %d\n", ret);
> >
> > I don't think this is what you want; you had it right in previous
> > revisions:
> >
> > if (!rtwdev->efuse.country_worldwide) {
> > if (regulatory_hint(hw->wiphy, rtwdev->efuse.country_code))
> > rtw_err( ... );
> > }
> >
> > Without the 'country_worlwide' check, you start "hinting" (even on
> > worldwide chips) that you really wanted "country" 00 only, and so we
> > *never* adapt to more strict country settings. That's not how world-wide
> > settings are supposed to work.
>
> It doesn't mean that we want country 00 only, we will get country notifies
> from stack, and we will apply it if we accept it. We don't want stack to change
> the channel plan for us.
I noted this to you privately, but I don't believe it's expected to
call regulatory_hint() with "00". See the kerneldoc:
* @alpha2: the ISO/IEC 3166 alpha2 the driver claims its regulatory domain
* should be in. If @rd is set this should be NULL. Note that if you
* set this to NULL you should still set rd->alpha2 to some accepted
* alpha2.
Note that "00" is *not* actually an ISO 3166 alpha2 code.
The key problem I'm seeing: once you do this, you establish a
wiphy-specific regd, and this regd never updates its country code or
DFS region according to IE updates. So attributes like
NL80211_ATTR_DFS_REGION and NL80211_ATTR_REG_ALPHA2 remain unset.
Your previous revision -- which for WW settings used
wiphy_apply_custom_regulatory() and *not* regulatory_hint() -- did not
have that problem.
> > Why are you ignoring SET_BY_DRIVER?
>
> Since the notification with NL80211_REGDOM_SET_BY_DRIVER flag might
> comes from an another chipset's regulatory_hint().
Ack.
Brian
