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Date:   Thu, 28 Mar 2019 14:06:07 -0700
From:   Jakub Kicinski <jakub.kicinski@netronome.com>
To:     Michal Kubecek <mkubecek@suse.cz>
Cc:     Jiri Pirko <jiri@resnulli.us>,
        Florian Fainelli <f.fainelli@gmail.com>,
        David Miller <davem@davemloft.net>, netdev@vger.kernel.org,
        Andrew Lunn <andrew@lunn.ch>,
        John Linville <linville@tuxdriver.com>,
        Stephen Hemminger <stephen@networkplumber.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next v5 12/22] ethtool: provide string sets with
 GET_STRSET request
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On Thu, 28 Mar 2019 21:43:29 +0100, Michal Kubecek wrote:
> On Thu, Mar 28, 2019 at 11:52:56AM -0700, Jakub Kicinski wrote:
> > On Thu, 28 Mar 2019 18:35:24 +0100, Jiri Pirko wrote:  
> > > Thu, Mar 28, 2019 at 03:04:28PM CET, mkubecek@suse.cz wrote:  
> > > >On Thu, Mar 28, 2019 at 02:43:13PM +0100, Jiri Pirko wrote:    
> > > >> 
> > > >> I don't like this. This should not be bitfield/set. This should be
> > > >> simply nested array of enum values:
> > > >> 
> > > >> enum ethtool_link_mode {
> > > >> 	ETHTOOL_LINK_MODE_10baseT_Half,
> > > >> 	ETHTOOL_LINK_MODE_10baseT_Full,
> > > >> 	ETHTOOL_LINK_MODE_100baseT_Half,
> > > >> 	ETHTOOL_LINK_MODE_100baseT_Full,
> > > >> 	ETHTOOL_LINK_MODE_1000baseT_Full,
> > > >> };    
> > > >
> > > >We already have such enum. The problem with your "no string" approach is
> > > >that it requires all userspace applications to (1) keep this enum in    
> > > 
> > > That is how it is usually done. UAPI defines ATTRS and values, userspace
> > > assigns appropriate strings.  
> > 
> > +1 FWIW, I'm with Jiri on the string situation.  
> 
> And I'm still waiting for any of you to tell me how would you handle
> private flags, stats, tests etc. without the string sets.
> 
> Ditching the verbose form of bit sets would be a nuisance for userspace
> using the interface but compared to e.g. having to mix three different
> kernel interfaces, it's just a minor problem. Ditching the static string
> sets would mean giving up the opportunity to get rid of having to sync
> all kinds of tables with every userspace consumer whenever a new flag is
> introduced. Pity... but still doable. But how do you want to do without
> the string sets which are provided by drivers?

I don't think there is a disagreement about stuff which is private to
the driver.  The strings have to be exposed there.