[openwrt/openwrt] generic: net: phy: be more conservative about MAC interface selection

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/ee03a2742ba450409b9d82228064c08b1c35e800

commit ee03a2742ba450409b9d82228064c08b1c35e800
Author: Daniel Golle <daniel at makrotopia.org>
AuthorDate: Fri Oct 11 04:42:09 2024 +0100

    generic: net: phy: be more conservative about MAC interface selection
    
    Only add SerDes interface modes at lower speeds to host_interfaces.
    
    Fixes: 5281033831 ("generic: net: phy: use all SerDes MAC interface modes")
    Signed-off-by: Daniel Golle <daniel at makrotopia.org>
---
 ...pulate-host_interfaces-when-attaching-PHY.patch | 33 ++++++++++++++++++----
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/target/linux/generic/pending-6.6/706-net-phy-populate-host_interfaces-when-attaching-PHY.patch b/target/linux/generic/pending-6.6/706-net-phy-populate-host_interfaces-when-attaching-PHY.patch
index bd2d015b17..78e0049f05 100644
--- a/target/linux/generic/pending-6.6/706-net-phy-populate-host_interfaces-when-attaching-PHY.patch
+++ b/target/linux/generic/pending-6.6/706-net-phy-populate-host_interfaces-when-attaching-PHY.patch
@@ -1,4 +1,4 @@
-From 9e1a0d2006bc108b239b5bc00b42c2a8cc651217 Mon Sep 17 00:00:00 2001
+From 4e432e530db0056450fbc4a3cee793f16adc39a7 Mon Sep 17 00:00:00 2001
 From: Daniel Golle <daniel at makrotopia.org>
 Date: Tue, 8 Oct 2024 23:58:41 +0100
 Subject: [PATCH] net: phy: populate host_interfaces when attaching PHY
@@ -15,18 +15,39 @@ full-duplex only.
 
 Signed-off-by: Daniel Golle <daniel at makrotopia.org>
 ---
- drivers/net/phy/phylink.c | 7 +++++++
- 1 file changed, 7 insertions(+)
+ drivers/net/phy/phylink.c | 21 ++++++++++++++++++++-
+ 1 file changed, 20 insertions(+), 1 deletion(-)
 
 --- a/drivers/net/phy/phylink.c
 +++ b/drivers/net/phy/phylink.c
-@@ -2044,6 +2044,13 @@ int phylink_fwnode_phy_connect(struct ph
+@@ -2017,7 +2017,7 @@ int phylink_fwnode_phy_connect(struct ph
+ {
+ 	struct fwnode_handle *phy_fwnode;
+ 	struct phy_device *phy_dev;
+-	int ret;
++	int i, ret;
+ 
+ 	/* Fixed links and 802.3z are handled without needing a PHY */
+ 	if (pl->cfg_link_an_mode == MLO_AN_FIXED ||
+@@ -2044,6 +2044,25 @@ int phylink_fwnode_phy_connect(struct ph
  		pl->link_config.interface = pl->link_interface;
  	}
  
-+	/* Assume SerDes interface modes share the same lanes and allow
-+	 * the PHY to switch between them
++	/* Assume single-lane SerDes interface modes share the same
++	 * lanes and allow the PHY to switch to slower also supported modes
 +	 */
++	for (i = ARRAY_SIZE(phylink_sfp_interface_preference) - 1; i >= 0; i--) {
++		/* skip unsupported modes */
++		if (!test_bit(phylink_sfp_interface_preference[i], pl->config->supported_interfaces))
++			continue;
++
++		__set_bit(phylink_sfp_interface_preference[i], phy_dev->host_interfaces);
++
++		/* skip all faster modes */
++		if (phylink_sfp_interface_preference[i] == pl->link_interface)
++			break;
++	}
++
 +	if (test_bit(pl->link_interface, phylink_sfp_interfaces))
 +		phy_interface_and(phy_dev->host_interfaces, phylink_sfp_interfaces,
 +				  pl->config->supported_interfaces);