Subject: Re: [PATCH net-next 1/5] bridge: initialize port flags with switchdev defaults

From: Andrew Lunn <[email-masked]>
Date: Sat, 10 Mar 2018 17:30:50 +0100

On Fri, Mar 09, 2018 at 07:03:04PM -0800, Igor Mitsyanko wrote:
> Default bridge port flags for switchdev devices can be different from
> what is used in bridging core. Get default value from switchdev itself
> on port initialization.
> 
> Signed-off-by: Igor Mitsyanko <[email-masked]>
> ---
>  net/bridge/br_if.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
> index 9ba4ed6..d658b55 100644
> --- a/net/bridge/br_if.c
> +++ b/net/bridge/br_if.c
> @@ -342,6 +342,21 @@ static int find_portno(struct net_bridge *br)
>  	return (index >= BR_MAX_PORTS) ? -EXFULL : index;
>  }
>  
> +static unsigned long nbp_flags_get_default(struct net_device *dev)
> +{
> +	struct switchdev_attr attr = {
> +		.orig_dev = dev,
> +		.id = SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS,
> +	};
> +	int ret;
> +
> +	ret = switchdev_port_attr_get(dev, &attr);
> +	if (ret)
> +		return BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;

Hi Igor

Please check if ret == -EOPNOTSUPP and only then use the defaults. A
real error should be propagated, causing new_nbp to fail. You might
also consider what to do when ENODATA is returned.

     Andrew