netdev - Re: [PATCH v2] ethernet driver for the WIZnet W5300 chip

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1332435449.2461.8.camel@bwh-desktop.uk.solarflarecom.com>
Date:	Thu, 22 Mar 2012 16:57:29 +0000
From:	Ben Hutchings <bhutchings@...arflare.com>
To:	Mike Sinkovsky <msink@...monline.ru>
CC:	<netdev@...r.kernel.org>
Subject: Re: [PATCH v2] ethernet driver for the WIZnet W5300 chip

On Wed, 2012-03-21 at 12:20 +0600, Mike Sinkovsky wrote:
> 21.03.2012 0:08, Ben Hutchings написал:
> > +static void w5300_get_drvinfo(struct net_device *ndev,
> > +			      struct ethtool_drvinfo *info)
> > +{
> > +	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
> > +	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
> > +	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
> > [...]
> >
> > Nitpick: if you don't have firmware, don't set fw_version at all.
> >
> > Ben.
> 
> Then ethtool prints empty string as firmware version, I think "N/A" is 
> more intuitive.

Well, we can replace it with "N/A" in ethtool if that's what people want
to see.  But it should not be necessary for every driver that can't
report a firmware version to write this special string.

> Can will remove, if it is preferred way.

It is, and the various other drivers that used this string have recently
been changed.

> But I have a question to networking guru's:
> 
> This chip have FRAME_SIZE limited to 1514, including eth header.
> So, for 802.1Q vlan packets mtu must be set to 1496.
>
> For now we handle this from userspace, but I think this is wrong in general
> - handling hardware bugs and limitations is kernels job.
> 
> Can driver somehow limit mtu for slave vlan devices to 1496, but still 
> use 1500
> for plain ethernet?
> ->ndo_change_mtu is called for master device only, not for it's slaves.

I don't think it's possible to do this at the moment.  You can only set
NETIF_F_VLAN_CHALLENGED, which unfortunately disables VLAN sub-devices
entirely.

> (and sorry for my russian english, just in case)

Not to worry - your writing is quite clear.

Ben.

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

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html