Re: [patch net-next 3/9] mlx4: Implement port type setting via devlink interface

Tue, Feb 23, 2016 at 06:31:39PM CET, stephen@networkplumber.org wrote:

On Tue, 23 Feb 2016 12:26:00 +0100
Hannes Frederic Sowa [off-list ref] wrote:

quoted

Hi Jiri,

On 22.02.2016 19:31, Jiri Pirko wrote:

quoted

From: Jiri Pirko <redacted>

So far, there has been an mlx4-specific sysfs file allowing user to
change port type to either Ethernet of InfiniBand. This is very
inconvenient.

Again, I want to express my concerns regarding all of this until this 
will be integrated into udev/systemd for stable device names. While one 
can build wrapper code around devlink to have stable devlink ports, I 
don't see a reason to include kernel code which actually has more 
problems than the sysfs approach. This harms admins to use those devices 
and will additionally require user space to write boiler plate code.

Thanks,
Hannes

I appreciate that you need to have a lighterweight model for
network devices. But have to agree with Hannes.

No, I don't need to have lighterweight model for network device. This
patch does nothing like that.

This code breaks the model expected by applications like Quagga, SNMP
and lots of other legacy code. Is this really going to work with the
legacy Linux model.

No, this patch does not break anything. The original netdev still stay.