Subject: Re: [PATCH] net-sysfs: allow changing sysfs carrier when interface is down

From: Stephen Hemminger <[email-masked]>
Date: Thu, 2 Jun 2022 11:14:01 -0700

On Thu, 2 Jun 2022 10:52:15 -0700
Jakub Kicinski <[email-masked]> wrote:

> On Thu, 2 Jun 2022 17:15:13 +0000 Joakim Tjernlund wrote:
> > > What is "our HW", what kernel driver does it use and why can't the
> > > kernel driver take care of making sure the device is not accessed
> > > when it'd crash the system?    
> > 
> > It is a custom asic with some homegrown controller. The full config path is too complex for kernel too
> > know and depends on user input.  
> 
> We have a long standing tradition of not caring about user space
> drivers in netdev land. I see no reason to merge this patch upstream.
> 
> > > > Maybe so but it seems to me that this limitation was put in place without much thought.    
> > > 
> > > Don't make unnecessary disparaging statements about someone else's work.
> > > Whoever that person was.    
> > 
> > That was not meant the way you read it, sorry for being unclear.
> > The commit from 2012 simply says:
> > net: allow to change carrier via sysfs
> >     
> >     Make carrier writable  
> 
> Yeah, IIUC the interface was created for software devices.

If you want to discussion of original patch see:
https://patchwork.ozlabs.org/project/netdev/patch/[email-masked]/

PS: if you have lots of userspace handling, you should be using netlink not sysfs for management