Re: [PATCH 2/4] Ethtool: convert get_sg/set_sg calls to hw_features flag

From: Ben Hutchings <bhutchings@solarflare.com>
To: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: netdev@vger.kernel.org, e1000-devel@lists.sourceforge.net,
	Steve Glendinning <steve.glendinning@smsc.com>,
	Greg Kroah-Hartman <gregkh@suse.de>,
	Rasesh Mody <rmody@brocade.com>,
	Debashis Dutt <ddutt@brocade.com>,
	Kristoffer Glembo <kristoffer@gaisler.com>,
	linux-driver@qlogic.com, linux-net-drivers@solarflare.com
Subject: Re: [PATCH 2/4] Ethtool: convert get_sg/set_sg calls to hw_features flag
Date: Mon, 01 Nov 2010 21:15:50 +0000	[thread overview]
Message-ID: <1288646150.2231.62.camel@achroite.uk.solarflarecom.com> (raw)
In-Reply-To: <9d89236b6e4ff8c66937fbd7d8ce76602e680c5b.1288496404.git.mirq-linux@rere.qmqm.pl>

On Sat, 2010-10-30 at 06:28 +0200, Michał Mirosław wrote:
[...]
> @@ -1088,7 +1076,19 @@ static int __ethtool_set_sg(struct net_device *dev, u32 data)
>  		if (err)
>  			return err;
>  	}
> -	return dev->ethtool_ops->set_sg(dev, data);
> +
> +	if (dev->ethtool_ops->hw_set_sg) {
> +		err = dev->ethtool_ops->hw_set_sg(dev, data);
> +		if (err)
> +			return min(err, 0);
> +	}
> +
> +	if (data)
> +		dev->features |= NETIF_F_SG;
> +	else
> +		dev->features &= ~NETIF_F_SG;
> +
> +	return 0;
>  }
[...]

The odd semantics of positive return values really need to be documented
- both in the commit message and in the comment on struct ethtool_ops.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.