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From: Vivien Didelot <vivien.didelot@savoirfairelinux•com>
To: Andrew Lunn <andrew@lunn•ch>
Cc: netdev <netdev@vger•kernel.org>,
	Florian Fainelli <f.fainelli@gmail•com>,
	John Crispin <john@phrozen•org>,
	Bryan.Whitehead@microchip•com
Subject: Re: [RFC PATCH 09/16] dsa: dsa: Split up creating/destroying of DSA and CPU ports
Date: Fri, 27 May 2016 12:36:48 -0400	[thread overview]
Message-ID: <87fut35ufz.fsf@ketchup.mtl.sfl> (raw)
In-Reply-To: <20160527150744.GC20214@lunn.ch>

Hi Andrew,

Andrew Lunn <andrew@lunn•ch> writes:

> On Fri, May 27, 2016 at 10:33:49AM -0400, Vivien Didelot wrote:
>> Hi Andrew,
>> 
>> Andrew Lunn <andrew@lunn•ch> writes:
>> 
>> > -static void dsa_switch_destroy(struct dsa_switch *ds)
>> > +void dsa_cpu_dsa_destroy(struct device_node *port_dn)
>> >  {
>> > -	struct device_node *port_dn;
>> >  	struct phy_device *phydev;
>> > +
>> > +	if (of_phy_is_fixed_link(port_dn)) {
>> > +		phydev = of_phy_find_device(port_dn);
>> > +		if (phydev) {
>> > +			phy_device_free(phydev);
>> > +			fixed_phy_unregister(phydev);
>> > +		}
>> > +	}
>> > +}
>> > +
>> > +static void dsa_switch_destroy(struct dsa_switch *ds)
>> > +{
>> >  	int port;
>> >  
>> >  #ifdef CONFIG_NET_DSA_HWMON
>> > @@ -445,17 +467,11 @@ static void dsa_switch_destroy(struct dsa_switch *ds)
>> >  		dsa_slave_destroy(ds->ports[port].netdev);
>> >  	}
>> >  
>> > -	/* Remove any fixed link PHYs */
>> > +	/* Disable configuration of the CPU and DSA ports */
>> >  	for (port = 0; port < DSA_MAX_PORTS; port++) {
>> > -		port_dn = ds->ports[port].dn;
>> > -		if (of_phy_is_fixed_link(port_dn)) {
>> > -			phydev = of_phy_find_device(port_dn);
>> > -			if (phydev) {
>> > -				phy_device_free(phydev);
>> > -				of_node_put(port_dn);
>> 
>> Why does dsa_cpu_dsa_destroy drop that of_node_put call?
>
> The of node reference counting is broken. The DT maintainers actually
> say not to care, the whole reference counting scheme is broken. Which
> is a bit sad really. There was a discussion about this a couple of
> months ago.
>
> Anyway, the reference is taken in dsa_of_probe() as part of the
> or_each_available_child_of_node(child, port). This reference has
> nothing to do with the port being a fixed link or not. So freeing it
> here is inappropriate. The correct place to free it would probably be
> in dsa_of_remove.

OK, good to know. Can you split that in its own patch (prefered), or at
least document that in the commit message?

>> > -				fixed_phy_unregister(phydev);
>> > -			}
>> > -		}
>> > +		if ((dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
>> > +			continue;
>> 
>> Why do we skip DSA and CPU ports here? The previous code didn't.
>> 
>> > +		dsa_cpu_dsa_destroy(ds->ports[port].dn);
>
> They are now destroyed by the newly added dsa_cpu_dsa_destroy().  I'm
> making the code more symmetrical and easier to re-use. The inverse of
> this function is dsa_switch_setup_one() and it also uses a helper
> function to setup the dsa and cpu ports, dsa_cpu_dsa_setups().

But dsa_cpu_dsa_destroy() is not called here. Shouldn't we drop (like
before) or at least invert the condition above?

Thanks,

        Vivien

  reply	other threads:[~2016-05-27 16:36 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-27  1:20 [RFC PATCH 00/16] New DSA bind, switches as devices Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 01/16] dsa: slave: chip data is optional, don't dereference NULL Andrew Lunn
2016-05-27 18:45   ` Vivien Didelot
2016-05-27 21:24     ` Florian Fainelli
2016-05-27  1:20 ` [RFC PATCH 02/16] net: dsa: mv88e6xxx: fix circular lock in PPU work Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 03/16] dsa: slave: Remove MDIO address from switch MDIO bus name Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 04/16] dsa: tag_{e}dsa.c: Remove dependency on platform data Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 05/16] dsa: Add a ports structure and use it in the switch structure Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 06/16] dsa: Move port device node into port structure Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 07/16] dsa: Remove dynamic allocate of routing table Andrew Lunn
2016-05-27 18:54   ` Vivien Didelot
2016-05-27  1:20 ` [RFC PATCH 08/16] dsa: Copy the routing table into the switch structure Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 09/16] dsa: dsa: Split up creating/destroying of DSA and CPU ports Andrew Lunn
2016-05-27 14:33   ` Vivien Didelot
2016-05-27 15:07     ` Andrew Lunn
2016-05-27 16:36       ` Vivien Didelot [this message]
2016-05-27 19:25   ` Vivien Didelot
2016-05-27 20:01     ` Andrew Lunn
2016-05-27 20:29     ` Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 10/16] net: dsa: mv88e6xxx: Only support EDSA tagging Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 11/16] net: dsa: Refactor selection of tag ops into a function Andrew Lunn
2016-05-27 19:35   ` Vivien Didelot
2016-05-27 20:11     ` Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 12/16] dsa: Make mdio bus optional Andrew Lunn
2016-05-27 14:55   ` Vivien Didelot
2016-05-27 15:18     ` Andrew Lunn
2016-05-27 16:38       ` Vivien Didelot
2016-05-27  1:20 ` [RFC PATCH 13/16] net: dsa: mv88e6xxx: Refactor MDIO so driver registers mdio bus Andrew Lunn
2016-05-27 19:45   ` Vivien Didelot
2016-05-27  1:20 ` [RFC PATCH 14/16] net: dsa: Add new binding implementation Andrew Lunn
2016-05-27 20:39   ` Vivien Didelot
2016-05-27 20:57     ` Andrew Lunn
2016-05-27 21:29       ` Florian Fainelli
2016-05-28  8:23         ` Richard Cochran
2016-05-27  1:20 ` [RFC PATCH 15/16] arm: dt: vf610-zii-devel-b: Make use of new DSA binding Andrew Lunn
2016-05-27  1:20 ` [RFC PATCH 16/16] dsa: Document new binding Andrew Lunn
2016-05-27 18:30 ` [RFC PATCH 00/16] New DSA bind, switches as devices Vivien Didelot

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