Patch "net: phylink: ensure PHY momentary link-fails are handled" has been added to the 6.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: phylink: ensure PHY momentary link-fails are handled

to the 6.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-phylink-ensure-phy-momentary-link-fails-are-hand.patch
and it can be found in the queue-6.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 10df8dc7814e42be2d6f27c98f15d9c50c080ffd
Author: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Date:   Tue Nov 12 16:20:00 2024 +0000

    net: phylink: ensure PHY momentary link-fails are handled
    
    [ Upstream commit 671154f174e0e7f242507cd074497661deb41bfd ]
    
    Normally, phylib won't notify changes in quick succession. However, as
    a result of commit 3e43b903da04 ("net: phy: Immediately call
    adjust_link if only tx_lpi_enabled changes") this is no longer true -
    it is now possible that phy_link_down() and phy_link_up() will both
    complete before phylink's resolver has run, which means it'll miss that
    pl->phy_state.link momentarily became false.
    
    Rename "mac_link_dropped" to be more generic "link_failed" since it will
    cover more than the MAC/PCS end of the link failing, and arrange to set
    this in phylink_phy_change() if we notice that the PHY reports that the
    link is down.
    
    This will ensure that we capture an EEE reconfiguration event.
    
    Fixes: 3e43b903da04 ("net: phy: Immediately call adjust_link if only tx_lpi_enabled changes")
    Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
    Reviewed-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
    Link: https://patch.msgid.link/E1tAtcW-002RBS-LB@xxxxxxxxxxxxxxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 51c526d227fab..ed60836180b78 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -78,7 +78,7 @@ struct phylink {
 	unsigned int pcs_neg_mode;
 	unsigned int pcs_state;
 
-	bool mac_link_dropped;
+	bool link_failed;
 	bool using_mac_select_pcs;
 
 	struct sfp_bus *sfp_bus;
@@ -1475,9 +1475,9 @@ static void phylink_resolve(struct work_struct *w)
 		cur_link_state = pl->old_link_state;
 
 	if (pl->phylink_disable_state) {
-		pl->mac_link_dropped = false;
+		pl->link_failed = false;
 		link_state.link = false;
-	} else if (pl->mac_link_dropped) {
+	} else if (pl->link_failed) {
 		link_state.link = false;
 		retrigger = true;
 	} else {
@@ -1572,7 +1572,7 @@ static void phylink_resolve(struct work_struct *w)
 			phylink_link_up(pl, link_state);
 	}
 	if (!link_state.link && retrigger) {
-		pl->mac_link_dropped = false;
+		pl->link_failed = false;
 		queue_work(system_power_efficient_wq, &pl->resolve);
 	}
 	mutex_unlock(&pl->state_mutex);
@@ -1793,6 +1793,8 @@ static void phylink_phy_change(struct phy_device *phydev, bool up)
 		pl->phy_state.pause |= MLO_PAUSE_RX;
 	pl->phy_state.interface = phydev->interface;
 	pl->phy_state.link = up;
+	if (!up)
+		pl->link_failed = true;
 	mutex_unlock(&pl->state_mutex);
 
 	phylink_run_resolve(pl);
@@ -2116,7 +2118,7 @@ EXPORT_SYMBOL_GPL(phylink_disconnect_phy);
 static void phylink_link_changed(struct phylink *pl, bool up, const char *what)
 {
 	if (!up)
-		pl->mac_link_dropped = true;
+		pl->link_failed = true;
 	phylink_run_resolve(pl);
 	phylink_dbg(pl, "%s link %s\n", what, up ? "up" : "down");
 }
@@ -2750,7 +2752,7 @@ int phylink_ethtool_set_pauseparam(struct phylink *pl,
 	 * link will cycle.
 	 */
 	if (manual_changed) {
-		pl->mac_link_dropped = true;
+		pl->link_failed = true;
 		phylink_run_resolve(pl);
 	}