[RFC,net-next,04/13] net: phylink: ensure link is down when changing interface

Message ID E1jqHFj-0006Og-5E@rmk-PC.armlinux.org.uk
State New
Headers show
Series
  • Phylink PCS updates
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Commit Message

Russell King June 30, 2020, 2:28 p.m.
The only PHYs that are used with phylink which change their interface
are the BCM84881 and MV88X3310 family, both of which only change their
interface modes on link-up events.  However, rather than relying upon
this behaviour by the PHY, we should give a stronger guarantee when
resolving that the link will be down whenever we change the interface
mode.  This patch implements that stronger guarantee for resolve.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phylink.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 8ffe5df5c296..1507ea8a9385 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -620,8 +620,18 @@  static void phylink_resolve(struct work_struct *w)
 		}
 	}
 
-	if (mac_config)
+	if (mac_config) {
+		if (link_state.interface != pl->link_config.interface) {
+			/* The interface has changed, force the link down and
+			 * then reconfigure.
+			 */
+			if (cur_link_state) {
+				phylink_link_down(pl);
+				cur_link_state = false;
+			}
+		}
 		phylink_mac_config(pl, &link_state);
+	}
 
 	if (link_state.link != cur_link_state) {
 		pl->old_link_state = link_state.link;