Re: [PATCH net-next v5 2/2] virtio_net: add ethtool support for set and get of settings

On Wed, Feb 03, 2016 at 10:19:04AM +0100, Nikolay Aleksandrov wrote:

On 02/03/2016 04:04 AM, Nikolay Aleksandrov wrote:

quoted

From: Nikolay Aleksandrov <redacted>

This patch allows the user to set and retrieve speed and duplex of the
virtio_net device via ethtool. Having this functionality is very helpful
for simulating different environments and also enables the virtio_net
device to participate in operations where proper speed and duplex are
required (e.g. currently bonding lacp mode requires full duplex). Custom
speed and duplex are not allowed, the user-supplied settings are validated
before applying.

Example:
$ ethtool eth1
Settings for eth1:
...
	Speed: Unknown!
	Duplex: Unknown! (255)
$ ethtool -s eth1 speed 1000 duplex full
$ ethtool eth1
Settings for eth1:
...
	Speed: 1000Mb/s
	Duplex: Full

Based on a patch by Roopa Prabhu.

Signed-off-by: Nikolay Aleksandrov <redacted>
---
v2: use the new ethtool speed/duplex validation functions and allow half
duplex to be set
v3: return error if the user tries to change anything besides speed/duplex
as per Michael's comment
We have to zero-out advertising as it gets set automatically by ethtool if
setting speed and duplex together.
v4: Set port type to PORT_OTHER
v5: null diff1.port because we set cmd->port now and ethtool returns it in
the set request, retested all cases

Hmm, nulling the advertising and ->port completely ignores them, i.e. won't produce
an error if the user actually specified a different value for either of them.
We can check if the ->port matches what we returned, but there's no fix for
advertising. I'm leaving both ignored for now, please let me know if you'd
prefer otherwise.

Thanks,
 Nik

I think I prefer validating port.
For advertising we don't allow enabling autonegotiation so ignoring
these is fine I think.

-- 
MST