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Date:   Thu, 21 Mar 2019 17:21:06 +0100
From:   Jiri Pirko <jiri@resnulli.us>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Michal Kubecek <mkubecek@suse.cz>,
        David Miller <davem@davemloft.net>, netdev@vger.kernel.org,
        Jakub Kicinski <jakub.kicinski@netronome.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        John Linville <linville@tuxdriver.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next v4 05/22] ethtool: introduce ethtool netlink
 interface
Message-ID: <20190321162105.GU2087@nanopsycho>
References: <cover.1553170807.git.mkubecek@suse.cz>
 <a5a50f3d60cee03f75b70fdf17e73a6212aaec3d.1553170807.git.mkubecek@suse.cz>
 <20190321135705.GB17655@lunn.ch>
 <20190321141343.GH29968@unicorn.suse.cz>
 <20190321152509.GB23408@lunn.ch>
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Thu, Mar 21, 2019 at 04:25:09PM CET, andrew@lunn.ch wrote:
>On Thu, Mar 21, 2019 at 03:13:43PM +0100, Michal Kubecek wrote:
>> On Thu, Mar 21, 2019 at 02:57:05PM +0100, Andrew Lunn wrote:
>> > On Thu, Mar 21, 2019 at 02:07:35PM +0100, Michal Kubecek wrote:
>> > > +static int __init ethnl_init(void)
>> > > +{
>> > > +	int ret;
>> > > +
>> > > +	ret = genl_register_family(&ethtool_genl_family);
>> > > +	if (ret < 0)
>> > > +		panic("ethtool: could not register genetlink family\n");
>> > 
>> > Panic seems a bit strong. Do we really want to kill the box because
>> > this fails?
>> 
>> When I switched CONFIG_ETHTOOL_NETLINK from tristate to bool, I checked
>> some other non-modular subsystems to see what they do on failed
>> initialization and each of them did handle it by panic() so I didn't
>> think about it too much and did the same.
>> 
>> Thinking about it now, if the family registration fails, the only entry
>> point to care about should be ethtool_notify() (I'll have to check more
>> carefully to be sure) so that adding a check there should be sufficient
>> to let everything work (except for the netlink interface, of course).
>
>Hi Michal
>
>So maybe do a WARN_ON() and return the error code.

+1

>
>Linus has been quite vocal about killing the box when there is no real
>need...
>
>	Andrew