Re: perm_addr get

Fri, Dec 21, 2012 at 02:09:55PM CET, bhutchings@solarflare.com wrote:

On Fri, 2012-12-21 at 14:01 +0100, Jiri Pirko wrote:

quoted

Hi all.

From what I understand dev->perm_addr is set only in case the hw has
permanent hw address somewhere written (for example EPROM).

So when I query device which does not have perm_addr set I get:

testt1:~$ ethtool -P team0
Permanent address: 00:00:00:00:00:00

Is this the correct behaviour? Wouldn't it be more correct if
ethtool_get_perm_addr() fails with -ENOENT for something like that?

I don't think we should change the implementation now, as someone might
depend on it.  It's trivial to distinguish this not-a-permanent-address
case.  However the ethtool command output could be improved.

Well, not change it even if it is not correct? And by "trivial to distinguish"
you mean 00:00:00:00:00:00 ~ device has no permanent address?
But in some cases (like vxge, mac80211) it's possible to see 00:00:00:00:00:00
by ethtool -P even though the device has permanent address (set later on, after
register_netdev call).

I think that ethtool_get_perm_addr should return:
-ENOENT if dev has no perm addr
-EAGAIN if dev perm addr hasn't been obtained yet
0 (and addr) in other cases
	
And how exactly should be the ethtool output improved?

Thanks

Jiri

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
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