Re: [PATCH 2/2] fpga: add FPGA manager debugfs

[Federico Vaga]

Hi,

On Thursday, August 16, 2018 10:04:51 PM CEST Alan Tull wrote:
> On Thu, Aug 16, 2018 at 1:59 PM, Moritz Fischer <mdf@xxxxxxxxxx> wrote:
> > Hi Alan,
> 
> Hi Moritz,
> 
> > comments inline. While I see how this is useful, I have the
> > suspicion that from the moment this gets merged vendor kernels
> > will just default to use this ...
> 
> Yeah, I have that suspicion as well.  That's probably why I sat on
> this and didn't upstream it for 2 years.  But on the other hand, I
> keep hearing of lots of cases of people implementing this
> independently anyway.  At least if it is debugfs, it makes it clear
> that it's not intended for production use.

I'm one of those guys who implemented this independently.

@Mortiz
I do not see how this can be a bad thing (from what you wrote I guess you 
prefer another interface). Which interface to use depends on the use case.
If you have this suspicion it's, I guess, because such interface it is 
extremely easy to use.

@Alan
DebugFS can be a first step, but I would go for a normal device in /dev at 
some point. I do not see why this should not be used in production

Below, again, my code that does the same thing. I already posted this in 
another thread [1] but probably this is the best place. As I said in the 
other thread, this is what I did quickly last year to make things working 
for us (where this kind of interface is a must). Unfortunately, I do not 
have time to review my own code and improve it.


[1] https://lkml.org/lkml/2018/8/16/107


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