ethtool: allow setting MDI-X state

A bit ago ethtool added support for reading MDI-X state, this
patch finishes the implementation, adding the complementary write
command.

Add support to ethtool for controlling the MDI-X (crossover)
state of a network port.  Most adapters correctly negotiate
MDI-X, but some ill-behaved switches have trouble and end up
picking the wrong MDI setting, which results in complete loss of
link.  Usually this error condition can be observed when multiple
ethtool -r ethX are required before link is achieved.

This patch allows the user to override the normal "auto" setting
and force the crossover state to on or off.

The set will fail if the driver doesn't support the get, as
suggested by Ben Hutchings.

setting MDI not supported

In addition the do_gset output was changed slightly to report the
value set by the user (when the driver supports the set)

old:
MDI-X: on

new:
MDI-X: on (auto)
or
MDI-X: on (forced)

usage is ethtool -s eth0 mdix [auto|on|off]

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Tested-by: Aaron Brown aaron.f.brown@intel.com
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

0 files changed, 0 insertions, 0 deletions