Subject: Re: [PATCH v3 2/4] bus: fsl-mc: add restool userspace support

From: Laurentiu Tudor <[email-masked]>
Date: Thu, 5 Apr 2018 12:16:20 +0000

On 04/05/2018 02:47 PM, Andrew Lunn wrote:
> On Thu, Apr 05, 2018 at 10:30:01AM +0000, Laurentiu Tudor wrote:
>> Hello,
>>
>> My 2c below.
>>
>> On 04/04/2018 03:42 PM, Andrew Lunn wrote:
>>>> I hear you.  It is more complicated this way...having all these individual
>>>> objects vs just a single "bundle" of them that represents a NIC.  But, that's
>>>> the way the DPAA2 hardware is, and we're implementing kernel support for
>>>> the hardware as it is.
>>>
>>> Hi Stuart
>>>
>>> I see we are not making any progress here.
>>>
>>> So what i suggest is you post the kernel code and configuration tool
>>> concept to netdev for a full review. You want reviews from David
>>> Miller, Jiri Pirko, Jakub Kicinski, David Ahern, etc.
>>>
>>
>> I think that the discussion steered too much towards networking related
>> topics, while this ioctl doesn't have much to do with networking.
>
> Hi Laurentiu
>
> So i can use switchdev without it? I can modprobe the switchdev
> driver, all the physical interfaces will appear, and i can use ip addr
> add etc. I do not need to use a user space tool at all in order to use
> the network functionality?

Absolutely!
In normal use cases the system designer, depending on the requirements, 
configures the various devices that it desires through a firmware 
configuration (think something like a device tree). The devices 
configured are presented on the mc-bus and probed normally by the 
kernel. The standard networking linux tools can be used as expected.

The ioctl is necessary only for more advanced use cases that are 
supported by this bus. Think "more dynamic" scenarios that involve 
linking & unlinking various devices at runtime, maybe some 
virtualization scenarios. Unfortunately I'm not the architect type of 
guy so I don't have more specific examples to better illustrate ...

---
Best Regards, Laurentiu