Re: [Bridge] [PATCH v2 net-next 03/11] net: bridge: don't print in br_switchdev_set_port_flag

[Vladimir Oltean <olteanv@gmail.com>]

On Tue, Feb 09, 2021 at 05:19:28PM +0200, Vladimir Oltean wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> Currently br_switchdev_set_port_flag has two options for error handling
> and neither is good:
> - The driver returns -EOPNOTSUPP in PRE_BRIDGE_FLAGS if it doesn't
>   support offloading that flag, and this gets silently ignored and
>   converted to an errno of 0. Nobody does this.
> - The driver returns some other error code, like -EINVAL, in
>   PRE_BRIDGE_FLAGS, and br_switchdev_set_port_flag shouts loudly.
>
> The problem is that we'd like to offload some port flags during bridge
> join and leave, but also not have the bridge shout at us if those fail.
> But on the other hand we'd like the user to know that we can't offload
> something when they set that through netlink. And since we can't have
> the driver return -EOPNOTSUPP or -EINVAL depending on whether it's
> called by the user or internally by the bridge, let's just add an extack
> argument to br_switchdev_set_port_flag and propagate it to its callers.
> Then, when we need offloading to really fail silently, this can simply
> be passed a NULL argument.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---

The build fails because since I started working on v2 and until I sent
it, Jakub merged net into net-next which contained this fix:
https://patchwork.kernel.org/project/netdevbpf/patch/20210207194733.1811529-1-olteanv@gmail.com/
for which I couldn't change prototype due to it missing in net-next.
I think I would like to rather wait to gather some feedback first before
respinning v3, if possible.