Userpace serial port

[Greg KH]

On Thu, Jun 11, 2015 at 08:39:39AM +0200, Ricardo Ribalda Delgado wrote:
> Hello Greg
> 
> On Thu, Jun 11, 2015 at 5:52 AM, Greg KH <greg at kroah.com> wrote:
> > On Wed, Jun 10, 2015 at 02:39:35PM +0200, Ricardo Ribalda Delgado wrote:
> 
> >> Nowadays there is a kernel land implementation of ethercat master, but
> >> it is not merged (and it is definately not an easy job). And a
> >> software implementation http://fh-soft.de/src/ethercat-userspace.html
> >
> > Why not attempt to merge it?
> 
> I have my doubts that this is the best option. If you need real time
> performance you need to run it in kernel-space where you need a
> ethercat protocol driver, a patch for your network card and an kernel
> module for your application.

real-time performance does not mean it has to be in the kernel at all.

And almost no one needs "real" real-time performance, that's a horrible
check-box that people love to claim is needed and yet, almost no one
really needs in the end.

> By looking at our applications, The userspace sollution is more than
> enough for our requirements.
> 
> The problem appears when we want to use the serial adapter.  I want to
> keep using the serial API, but I cannot achieve this from userspace.

I don't understand what type of API you are talking about here.  What
exactly does ethercat do?  What are you doing that does not work today
from userspace with the existing serial apis?

thanks,

greg k-h