Re: [dpdk-dev] [PATCH v2 1/5] kni: add API to set link status on kernel interface

[Dan Gora <dg@adax.com>]

On Thu, Sep 27, 2018 at 6:49 PM, Ferruh Yigit <ferruh.yigit@intel.com> wrote:
>>> It would be useful if it writes the values of virtual interface, but this API
>>> prints user input.
>>>
>> I'm sorry, Ferruh, I really don't understand what you are referring to
>> here.  What virtual interface are you talking about?
>
> Virtual interface is KNI interface, Linux virtual network interface.
>
>
> Let me try again,
>
> You are adding a new API to KNI library, which is to set link status of KNI
> interface.
>
> This API prints some link related values in its log. But these values are not
> applied to KNI interface or not the values coming from KNI interface. These are
> just values provided by user to the API, I am saying printing these values in
> log can be confusing, the user may think API applies these values to KNI interface.

Well, yes the link_status (link up, link down) _is_ applied to the KNI
interface.  When that occurs, most people want to know what the link
speed is that the link came up at.  Again, this is how every other
Ethernet driver in linux works.  I doubt that someone would be
confused by that.

If the KNI interface is purely virtual (that is, it does not
correspond to any physical Ethernet port), then the DPDK application
writer is under no obligation to use this API function, or they can
use it and just set the speed to 0.  If the end user understands that
the KNI interface is purely virtual, then they should not be confused
that the speed is 0 or that the duplex/autoNeg values are irrelevant.

I just don't see how this could cause any confusion.