Re: [PATCH] mwifiex: Add module parameter for regdomain

From: Paul Stewart <pstew@chromium.org>
To: "John W. Linville" <linville@tuxdriver.com>
Cc: Bing Zhao <bzhao@marvell.com>,
	Ben Greear <greearb@candelatech.com>,
	Kalle Valo <kvalo@adurom.com>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	Amitkumar Karwar <akarwar@marvell.com>,
	Avinash Patil <patila@marvell.com>,
	Yogesh Powar <yogeshp@marvell.com>,
	Nishant Sarmukadam <nishants@marvell.com>,
	Frank Huang <frankh@marvell.com>
Subject: Re: [PATCH] mwifiex: Add module parameter for regdomain
Date: Thu, 13 Jun 2013 10:33:00 -0700	[thread overview]
Message-ID: <CAMcMvsgVHMzVY4fnW7n+vgdWKKVgvF+fJ93xvRkkfZUjxt-bBQ@mail.gmail.com> (raw)
In-Reply-To: <20130613173002.GC3246@tuxdriver.com>

On Thu, Jun 13, 2013 at 10:30 AM, John W. Linville
<linville@tuxdriver.com> wrote:
>
> On Wed, Jun 12, 2013 at 12:01:23PM -0700, Bing Zhao wrote:
> >
> > > >> "iw reg set XX" or "country_code=XX" in hostapd.conf is a *user* hint.
> > > >>
> > > >> What we need here is a *driver* hint. Furthermore, with a driver
> > > >> regulatory hint, the passive-scan and no-ibss flags are cleared so we
> > > >> can start AP with hostapd on 5G band.
> > > >
> > > > So it's a driver hint which is coming from user space via a module
> > > > parameter. IMHO you are abusing interfaces here. Is there any better way
> > > > to solve your problem?
> > >
> > > It would be nice to have some way to do this for ath9k and other NICs
> > > as well.  Best I could come up with is a similar hack for ath9k.
> > >
> > > I think part of the problem is that this config info needs to be
> > > available very early in the module loading/init logic, so it's
> > > too late to be configured using 'iw' or similar.
> >
> > Exactly. regulatory_hint () needs to be called right after wiphy registration.
>
> It does seem a bit ugly.  But if Marvell wants it, I don't see any
> "regulatory" argument to disallow something like this.
>
> Does anyone have a better suggestion for a user interface for such
> a feature?

The only (slightly) cleaner thing I could think of is a module
parameter to cfg80211 so all drivers in the system would be made aware
of the boot-time regulatory domain.

>
>
> John
> --
> John W. Linville                Someday the world will need a hero, and you
> linville@tuxdriver.com                  might be all we have.  Be ready.