Re: [PATCH net-next v4 2/6] netdev_features: remove unused __UNUSED_NETIF_F_1
From: Eric Dumazet <edumazet@google.com>
Date: 2024-08-21 15:43:33
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On Wed, Aug 21, 2024 at 5:07 PM Alexander Lobakin [off-list ref] wrote:
NETIF_F_NO_CSUM was removed in 3.2-rc2 by commit 34324dc2bf27
("net: remove NETIF_F_NO_CSUM feature bit") and became
__UNUSED_NETIF_F_1. It's not used anywhere in the code.
Remove this bit waste.
It wasn't needed to rename the flag instead of removing it as
netdev features are not uAPI/ABI. Ethtool passes their names
and values separately with no fixed positions and the userspace
Ethtool code doesn't have any hardcoded feature names/bits, so
that new Ethtool will work on older kernels and vice versa.This is only true for recent enough ethtool (>= 3.4) You might refine the changelog to not claim this "was not needed". Back in 2011 (and linux-2.6.39) , this was needed for sure. I am not sure we have a documented requirement about ethtool versions.