Subject: Re: [patch net-next 07/13] dsa: implement ndo_swdev_get_id

From: Felix Fietkau <[email-masked]>
Date: Fri, 05 Sep 2014 06:43:23 +0200

On 2014-09-04 14:47, Jiri Pirko wrote:
> Thu, Sep 04, 2014 at 01:20:58AM CEST, [email-masked] wrote:
>>On 09/03/2014 02:24 AM, Jiri Pirko wrote:
>>> Signed-off-by: Jiri Pirko <[email-masked]>
>>> ---
>>>  include/linux/netdevice.h |  3 ++-
>>>  include/net/dsa.h         |  1 +
>>>  net/dsa/Kconfig           |  2 +-
>>>  net/dsa/dsa.c             |  3 +++
>>>  net/dsa/slave.c           | 10 ++++++++++
>>>  5 files changed, 17 insertions(+), 2 deletions(-)
>>> 
>>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>>> index 6a009d1..7ee070f 100644
>>> --- a/include/linux/netdevice.h
>>> +++ b/include/linux/netdevice.h
>>> @@ -41,7 +41,6 @@
>>>  
>>>  #include <linux/ethtool.h>
>>>  #include <net/net_namespace.h>
>>> -#include <net/dsa.h>
>>>  #ifdef CONFIG_DCB
>>>  #include <net/dcbnl.h>
>>>  #endif
>>> @@ -1259,6 +1258,8 @@ enum netdev_priv_flags {
>>>  #define IFF_LIVE_ADDR_CHANGE		IFF_LIVE_ADDR_CHANGE
>>>  #define IFF_MACVLAN			IFF_MACVLAN
>>>  
>>> +#include <net/dsa.h>
>>> +
>>>  /**
>>>   *	struct net_device - The DEVICE structure.
>>>   *		Actually, this whole structure is a big mistake.  It mixes I/O
>>> diff --git a/include/net/dsa.h b/include/net/dsa.h
>>> index 9771292..d60cd42 100644
>>> --- a/include/net/dsa.h
>>> +++ b/include/net/dsa.h
>>> @@ -140,6 +140,7 @@ struct dsa_switch {
>>>  	u32			phys_mii_mask;
>>>  	struct mii_bus		*slave_mii_bus;
>>>  	struct net_device	*ports[DSA_MAX_PORTS];
>>> +	struct netdev_phys_item_id psid;
>>>  };
>>>  
>>>  static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
>>> diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
>>> index a585fd6..4e144a2 100644
>>> --- a/net/dsa/Kconfig
>>> +++ b/net/dsa/Kconfig
>>> @@ -1,6 +1,6 @@
>>>  config HAVE_NET_DSA
>>>  	def_bool y
>>> -	depends on NETDEVICES && !S390
>>> +	depends on NETDEVICES && NET_SWITCHDEV && !S390
>>
>>It does not look like this is necessary, we are only using definitions
>>from net/dsa.h and include/linux/netdevice.h, and if it was, a 'select'
>>would be more appropriate here I think.
>>
>>TBH, I think we should rather drop this patch for now, I do not see any
>>benefit in providing a random id over no-id at all.
> 
> Well, the benefit is that you are still able to see which ports belong
> to the same switch.
I think it's a bad idea to force switchdev bloat onto DSA users just for
that random id thing.

- Felix