Commit 45c767fa authored by Russell King's avatar Russell King Committed by David S. Miller

net: add linkmode helper for setting flow control advertisement

Add a linkmode helper to set the flow control advertisement in an
ethtool linkmode mask according to the tx/rx capabilities. This
implementation is moved from phylib, and documented with an
analysis of its shortcomings.
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a87ae8a9
......@@ -42,3 +42,54 @@ void linkmode_resolve_pause(const unsigned long *local_adv,
}
}
EXPORT_SYMBOL_GPL(linkmode_resolve_pause);
/**
* linkmode_set_pause - set the pause mode advertisement
* @advertisement: advertisement in ethtool format
* @tx: boolean from ethtool struct ethtool_pauseparam tx_pause member
* @rx: boolean from ethtool struct ethtool_pauseparam rx_pause member
*
* Configure the advertised Pause and Asym_Pause bits according to the
* capabilities of provided in @tx and @rx.
*
* We convert as follows:
* tx rx Pause AsymDir
* 0 0 0 0
* 0 1 1 1
* 1 0 0 1
* 1 1 1 0
*
* Note: this translation from ethtool tx/rx notation to the advertisement
* is actually very problematical. Here are some examples:
*
* For tx=0 rx=1, meaning transmit is unsupported, receive is supported:
*
* Local device Link partner
* Pause AsymDir Pause AsymDir Result
* 1 1 1 0 TX + RX - but we have no TX support.
* 1 1 0 1 Only this gives RX only
*
* For tx=1 rx=1, meaning we have the capability to transmit and receive
* pause frames:
*
* Local device Link partner
* Pause AsymDir Pause AsymDir Result
* 1 0 0 1 Disabled - but since we do support tx and rx,
* this should resolve to RX only.
*
* Hence, asking for:
* rx=1 tx=0 gives Pause+AsymDir advertisement, but we may end up
* resolving to tx+rx pause or only rx pause depending on
* the partners advertisement.
* rx=0 tx=1 gives AsymDir only, which will only give tx pause if
* the partners advertisement allows it.
* rx=1 tx=1 gives Pause only, which will only allow tx+rx pause
* if the other end also advertises Pause.
*/
void linkmode_set_pause(unsigned long *advertisement, bool tx, bool rx)
{
linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT, advertisement, rx);
linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, advertisement,
rx ^ tx);
}
EXPORT_SYMBOL_GPL(linkmode_set_pause);
......@@ -2361,22 +2361,7 @@ void phy_set_asym_pause(struct phy_device *phydev, bool rx, bool tx)
__ETHTOOL_DECLARE_LINK_MODE_MASK(oldadv);
linkmode_copy(oldadv, phydev->advertising);
linkmode_clear_bit(ETHTOOL_LINK_MODE_Pause_BIT,
phydev->advertising);
linkmode_clear_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
phydev->advertising);
if (rx) {
linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT,
phydev->advertising);
linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
phydev->advertising);
}
if (tx)
linkmode_change_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
phydev->advertising);
linkmode_set_pause(phydev->advertising, tx, rx);
if (!linkmode_equal(oldadv, phydev->advertising) &&
phydev->autoneg)
......
......@@ -92,4 +92,6 @@ void linkmode_resolve_pause(const unsigned long *local_adv,
const unsigned long *partner_adv,
bool *tx_pause, bool *rx_pause);
void linkmode_set_pause(unsigned long *advertisement, bool tx, bool rx);
#endif /* __LINKMODE_H */
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