Subject: [PATCH 31/49] net: phylink: ensure manual pause mode configuration takes effect

From: Russell King <[email-masked]>
Date: Tue, 23 Jun 2020 17:47:29 +0100

[ Upstream commit 2e919bc446faee429ac862a6cdb5e40017051f6b ]

We have been relying on link events and mac_config() when the manual
pause modes are changed.  With recent developments, such as moving
the programming of link state to mac_link_up(), this no longer works.

To ensure that we update the MAC, we must generate a link-down followed
by a link-up event; we can do that by setting mac_link_dropped and
triggering a resolve.

Fixes: 91a208f2185a ("net: phylink: propagate resolved link config via mac_link_up()")
Signed-off-by: Russell King <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/phy/phylink.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index b0ddeab2a8d2..ac38bead1cd2 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1480,6 +1480,8 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 				   struct ethtool_pauseparam *pause)
 {
 	struct phylink_link_state *config = &pl->link_config;
+	bool manual_changed;
+	int pause_state;
 
 	ASSERT_RTNL();
 
@@ -1494,15 +1496,15 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 	    !pause->autoneg && pause->rx_pause != pause->tx_pause)
 		return -EINVAL;
 
-	mutex_lock(&pl->state_mutex);
-	config->pause = 0;
+	pause_state = 0;
 	if (pause->autoneg)
-		config->pause |= MLO_PAUSE_AN;
+		pause_state |= MLO_PAUSE_AN;
 	if (pause->rx_pause)
-		config->pause |= MLO_PAUSE_RX;
+		pause_state |= MLO_PAUSE_RX;
 	if (pause->tx_pause)
-		config->pause |= MLO_PAUSE_TX;
+		pause_state |= MLO_PAUSE_TX;
 
+	mutex_lock(&pl->state_mutex);
 	/*
 	 * See the comments for linkmode_set_pause(), wrt the deficiencies
 	 * with the current implementation.  A solution to this issue would
@@ -1519,6 +1521,12 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 	linkmode_set_pause(config->advertising, pause->tx_pause,
 			   pause->rx_pause);
 
+	manual_changed = (config->pause ^ pause_state) & MLO_PAUSE_AN ||
+			 (!(pause_state & MLO_PAUSE_AN) &&
+			   (config->pause ^ pause_state) & MLO_PAUSE_TXRX_MASK);
+
+	config->pause = pause_state;
+
 	if (!pl->phydev && !test_bit(PHYLINK_DISABLE_STOPPED,
 				     &pl->phylink_disable_state))
 		phylink_pcs_config(pl, true, &pl->link_config);
@@ -1534,6 +1542,15 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 		phy_set_asym_pause(pl->phydev, pause->rx_pause,
 				   pause->tx_pause);
 
+	/* If the manual pause settings changed, make sure we trigger a
+	 * resolve to update their state; we can not guarantee that the
+	 * link will cycle.
+	 */
+	if (manual_changed) {
+		pl->mac_link_dropped = true;
+		phylink_run_resolve(pl);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(phylink_ethtool_set_pauseparam);
-- 
2.26.2