From mboxrd@z Thu Jan  1 00:00:00 1970
From: Fabio Baltieri <fabio.baltieri@gmail.com>
Subject: Re: [PATCH] can: rename LED trigger name on netdev renames
Date: Thu, 6 Sep 2012 22:46:00 +0200
Message-ID: <20120906204559.GB4043@gmail.com>
References: <20120904071128.GB416@vandijck-laurijssen.be>
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 <20120906185938.GA4043@gmail.com>
 <5048F9FB.9020207@hartkopp.net>
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To: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Kurt Van Dijck <kurt.van.dijck@eia.be>, Marc Kleine-Budde <mkl@pengutronix.de>, Wolfgang Grandegger <wg@grandegger.com>, linux-kernel@vger.kernel.org, linux-can@vger.kernel.org

On Thu, Sep 06, 2012 at 09:31:07PM +0200, Oliver Hartkopp wrote:
> >> +
> >> +/*
> >> + * NETDEV rename notifier to rename the associated led triggers too
> >> + */
> >> +static int can_led_notifier(struct notifier_block *nb, unsigned long msg,
> >> +			void *data)
> >> +{
> >> +	struct net_device *netdev = (struct net_device *)data;
> >> +	struct can_priv *priv = netdev_priv(netdev);
> >> +	int busy = 0;
> >> +
> >> +	if (!net_eq(dev_net(netdev), &init_net))
> >> +		return NOTIFY_DONE;
> >> +
> >> +	if (netdev->type != ARPHRD_CAN)
> >> +		return NOTIFY_DONE;
> >> +
> >> +	if (msg != NETDEV_CHANGENAME)
> >> +		return NOTIFY_DONE;
> > 
> > That's the main problem, which I also got stuck into when I did my first
> > can-led implementation.  As LED structures are in netdev's private data,
> > you can only use it if your driver is based on the can-dev API, and
> > there are no way to be sure of that if you get outside driver's code
> > itself.
> > 
> > This would give problems with vcan, slcan, and probabily other
> > non-mainlined drivers.
> 
> 
> Do you think, this is really a problem?
> 
> If a driver decides not to use the can-dev framework it has to implement own
> solutions or just adopt can-dev.

Agreed, but this still means that we can't assume that
netdev_priv(netdev) to a netdev where netdev->type == ARPHRD_CAN points
to a struct can_priv, right?

Fabio