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Date:   Tue, 17 May 2022 12:49:42 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Alexander Aring <aahringo@redhat.com>
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Network Development <netdev@vger.kernel.org>,
        edumazet@google.com, Paolo Abeni <pabeni@redhat.com>,
        johannes@sipsolutions.net, Alexander Aring <alex.aring@gmail.com>,
        Stefan Schmidt <stefan@datenfreihafen.org>,
        mareklindner@neomailbox.ch, sw@simonwunderlich.de, a@unstable.cc,
        sven@narfation.org, linux-wireless@vger.kernel.org,
        linux-wpan - ML <linux-wpan@vger.kernel.org>
Subject: Re: [PATCH net-next] net: ifdefy the wireless pointers in struct
 net_device
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On Tue, 17 May 2022 15:33:02 -0400 Alexander Aring wrote:
> > Could not we move to an union of pointers in the future since in many
> > cases a network device can only have one of those pointers at any given
> > time?  
> 
> note that ieee802154 has also functionality like __dev_get_by_index()
> and checks via "if (netdev->ieee802154_ptr)" if it's a wpan interface
> or not, guess the solution would be like it's done in wireless then.


Ack, but that code must live somewhere under

#if IS_ENABLED(CONFIG_IEEE802154) || IS_ENABLED(CONFIG_6LOWPAN)

otherwise I think I'd see a build failure. I guess a nice thing about
having the typed pointers is that we can depend on the compiler for
basic checking :)