Re: [RFC PATCH net-next v2 10/17] ethtool: implement GET_SETTINGS message

From: Michal Kubecek <mkubecek@suse.cz>
To: Andrew Lunn <andrew@lunn.ch>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Jiri Pirko <jiri@resnulli.us>, David Miller <davem@davemloft.net>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Roopa Prabhu <roopa@cumulusnetworks.com>,
	Jakub Kicinski <kubakici@wp.pl>,
	"John W. Linville" <linville@tuxdriver.com>
Subject: Re: [RFC PATCH net-next v2 10/17] ethtool: implement GET_SETTINGS message
Date: Tue, 21 Aug 2018 11:32:46 +0200	[thread overview]
Message-ID: <20180821093245.ktattosaduf6jvya@unicorn.suse.cz> (raw)
In-Reply-To: <20180730185455.GJ2983@lunn.ch>

On Mon, Jul 30, 2018 at 08:54:55PM +0200, Andrew Lunn wrote:
> > +/* Internal kernel helper to query a device ethtool_link_settings.
> > + *
> > + * Backward compatibility note: for compatibility with legacy drivers
> > + * that implement only the ethtool_cmd API, this has to work with both
> > + * drivers implementing get_link_ksettings API and drivers
> > + * implementing get_settings API. When drivers implement get_settings
> > + * and report ethtool_cmd deprecated fields
> > + * (transceiver/maxrxpkt/maxtxpkt), these fields are silently ignored
> > + * because the resulting struct ethtool_link_settings does not report them.
> 
> ~/linux/drivers$ grep -r [.]get_settings *
> net/ethernet/8390/etherh.c:		 .get_settings	= etherh_get_settings,
> 
> I don't think it is worth adding support for .get_settings for just
> one driver. It is better to just convert that driver to the new API.

I have prepared a patch converting 8390/etherh driver to use
{g,s}et_link_ksettings and I'm going to submit it when net-next opens.
Do you think we can then drop {g,s}et_settings callbacks completely
(i.e. also from ioctl() code and ethtool_ops)?  Do we care about
unconverted out of tree drivers?

Michal Kubecek