netdev - (repost for 2020y) inconsistency of ethtool feature names for get vs. set

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Message-ID: <36ca2996-ea04-f050-5f88-7edef5a88f26@yandex.ru>
Date:   Wed, 8 Apr 2020 16:07:39 +0300
From:   Konstantin Kharlamov <hi-angel@...dex.ru>
To:     netdev@...r.kernel.org
Cc:     linville@...driver.com
Subject: (repost for 2020y) inconsistency of ethtool feature names for get vs.
 set

I just started using the -K and -k options, and I was very confused why nothing I was trying worked. I followed the documentation, which says that there're predefined options, (e.g. gso, gro) but kernel may also define others. And according to the `-k` output, sure they were, like "generic-segmentation-offload" and "large-receive-offload"! Well, at least I thought so.

Researching the internet led me to the old report of this behavior. So, it was already discussed in 2014, someone got a patch to fix this, and everyone was happy. The patch has never made it into the discussion though.

I figured, the project has no bugtracker, so once discussion stopped, a report is lost. I guess, 6 years is a big enough timespan to consider a discussion stopped, so I'm bringing it up again. What follows is a copy of the report here https://www.spinics.net/lists/netdev/msg264222.html

P.S.: please add me to CC, I'm not subscribed to the list.

------

Hi Ben,

I noticed some inconsistency of feature names with the ethtool getting/setting of features mechanics -- the name of the feature you need to set (through -K) isn't what displayed by the get (-k) directive, here's an example:

$ ethtool -k eth1  | grep generic-receive-offload
generic-receive-offload: on

$ ethtool -K eth1  generic-receive-offload off
ethtool: bad command line argument(s)
For more information run ethtool -h

--> looking in the sources and realizing I need to use "rx-gro"

$ ethtool -K eth1  rx-gro on

$ethtool -k eth1  | grep generic-receive-offload
generic-receive-offload: on

same problem for rx checksum which is displayed as "rx-checksumming" by the get (-k)
but need to be "rx-checksum" for the set (-K) directive.