ethtool: Call ethtool's get/set_settings callbacks with cleaned data

This makes sure that when a driver calls the ethtool's
get/set_settings() callback of another driver, the data passed to it
is clean. This guarantees that speed_hi will be zeroed correctly if
the called callback doesn't explicitely set it: we are sure we don't
get a corrupted speed from the underlying driver. We also take care of
setting the cmd field appropriately (ETHTOOL_GSET/SSET).

This applies to dev_ethtool_get_settings(), which now makes sure it
sets up that ethtool command parameter correctly before passing it to
drivers. This also means that whoever calls dev_ethtool_get_settings()
does not have to clean the ethtool command parameter. This function
also becomes an exported symbol instead of an inline.

All drivers visible to make allyesconfig under x86_64 have been
updated.

Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/mdio.c

@@ -176,6 +176,9 @@ static u32 mdio45_get_an(const struct mdio_if_info *mdio, u16 addr)
  * @npage_adv: Modes currently advertised on next pages
  * @npage_lpa: Modes advertised by link partner on next pages
  *
+ * The @ecmd parameter is expected to have been cleared before calling
+ * mdio45_ethtool_gset_npage().
+ *
  * Since the CSRs for auto-negotiation using next pages are not fully
  * standardised, this function does not attempt to decode them.  The
  * caller must pass them in.