Maxim Mikityanskiy 840110a4ea ethtool: Fix preserving of wanted feature bits in netlink interface
Currently, ethtool-netlink calculates new wanted bits as:
(req_wanted & req_mask) | (old_active & ~req_mask)

It completely discards the old wanted bits, so they are forgotten with
the next ethtool command. Sample steps to reproduce:

1. ethtool -k eth0
   tx-tcp-segmentation: on # TSO is on from the beginning
2. ethtool -K eth0 tx off
   tx-tcp-segmentation: off [not requested]
3. ethtool -k eth0
   tx-tcp-segmentation: off [requested on]
4. ethtool -K eth0 rx off # Some change unrelated to TSO
5. ethtool -k eth0
   tx-tcp-segmentation: off # "Wanted on" is forgotten

This commit fixes it by changing the formula to:
(req_wanted & req_mask) | (old_wanted & ~req_mask),
where old_active was replaced by old_wanted to account for the wanted
bits.

The shortcut condition for the case where nothing was changed now
compares wanted bitmasks, instead of wanted to active.

Fixes: 0980bfcd69 ("ethtool: set netdev features with FEATURES_SET request")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-18 16:00:24 -07:00
2020-08-17 14:32:44 -07:00
2020-08-16 13:04:57 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.3 GiB
Languages
C 97.5%
Assembly 1%
Shell 0.6%
Python 0.3%
Makefile 0.3%