Message-ID: <1483427177.15591.5.camel@sipsolutions.net> (sfid-20170103_080624_699624_2C6703B1)
Subject: Re: [PATCH V3 2/2] cfg80211: support ieee80211-freq-limit DT
 property
From: Johannes Berg <johannes@sipsolutions.net>
To: =?UTF-8?Q?Rafa=C5=82_Mi=C5=82ecki?= <zajec5@gmail.com>
Cc: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Felix Fietkau <nbd@nbd.name>,
        Arend van Spriel <arend@broadcom.com>,
        Arnd Bergmann <arnd@arndb.de>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        =?UTF-8?Q?Rafa=C5=82_Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Tue, 03 Jan 2017 08:06:17 +0100
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> When driver uses custom regulatory it registers initial channels at
> init but it can also react to regdom changes using reg_notifier. Is
> that correct?

We can treat regulatory and OF data as entirely independent, I think.
At least that's my suggestion:

 * use OF data to populate the original channel list, saying which
   channels are valid (or not)
 * use regulatory later to further restrict settings of the channels

> So I'm looking at brcmf_cfg80211_reg_notifier which calls
> brcmf_setup_wiphybands which calls brcmf_construct_chaninfo.
> That last one reworks all channels on every call. It first marks all
> existing channels as DISABLED then queries firmware for the list of
> supported channels and updates wiphy channels one by one.
> So if I understand this correctly, every regdom change can result in
> rebuilding channels pretty much from the scratch. That's why I
> believed I need to call wiphy_freq_limits_apply on runtime, not just
> during the init.
> 
> Is there some flow in my understanding?

I think maybe there's a problem in my understanding :)

All the regulatory code usually takes into account channel->orig_flags. 
If this code also did, then we could have the original DISABLED flag
taken from OF still be valid here.

johannes

johannes