netdev - [PATCH net-next 3/3] net: phylink: add phylink_sfp_select_interface

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <E1uWu14-005KXo-IO@rmk-PC.armlinux.org.uk>
Date: Wed, 02 Jul 2025 10:44:34 +0100
From: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
To: Andrew Lunn <andrew@...n.ch>,
	Heiner Kallweit <hkallweit1@...il.com>
Cc: Alexander Duyck <alexander.duyck@...il.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	netdev@...r.kernel.org,
	Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH net-next 3/3] net: phylink: add
 phylink_sfp_select_interface_speed()

Add phylink_sfp_select_interface_speed() which attempts to select the
SFP interface based on the ethtool speed when autoneg is turned off.
This allows users to turn off autoneg for SFPs that support multiple
interface modes, and have an appropriate interface mode selected.

Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
---
 drivers/net/phy/phylink.c | 41 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index c92a878ab717..f5473510b762 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2709,6 +2709,39 @@ static phy_interface_t phylink_sfp_select_interface(struct phylink *pl,
 	return interface;
 }
 
+static phy_interface_t phylink_sfp_select_interface_speed(struct phylink *pl,
+							  u32 speed)
+{
+	phy_interface_t best_interface = PHY_INTERFACE_MODE_NA;
+	phy_interface_t interface;
+	u32 max_speed;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(phylink_sfp_interface_preference); i++) {
+		interface = phylink_sfp_interface_preference[i];
+		if (!test_bit(interface, pl->sfp_interfaces))
+			continue;
+
+		max_speed = phylink_interface_max_speed(interface);
+
+		/* The logic here is: if speed == max_speed, then we've found
+		 * the best interface. Otherwise we find the interface that
+		 * can just support the requested speed.
+		 */
+		if (max_speed >= speed)
+			best_interface = interface;
+
+		if (max_speed <= speed)
+			break;
+	}
+
+	if (best_interface == PHY_INTERFACE_MODE_NA)
+		phylink_err(pl, "selection of interface failed, speed %u\n",
+			    speed);
+
+	return best_interface;
+}
+
 static void phylink_merge_link_mode(unsigned long *dst, const unsigned long *b)
 {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask);
@@ -2911,8 +2944,14 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
 	 * link can be configured correctly.
 	 */
 	if (pl->sfp_bus) {
-		config.interface = phylink_sfp_select_interface(pl,
+		if (kset->base.autoneg == AUTONEG_ENABLE)
+			config.interface =
+				phylink_sfp_select_interface(pl,
 							config.advertising);
+		else
+			config.interface =
+				phylink_sfp_select_interface_speed(pl,
+							config.speed);
 		if (config.interface == PHY_INTERFACE_MODE_NA)
 			return -EINVAL;
 
-- 
2.30.2