openwrt/target/linux/generic/pending-6.6/706-net-phy-populate-host_interfaces-when-attaching-PHY.patch
Daniel Golle ee03a2742b 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@makrotopia.org>
2024-10-15 14:21:37 +01:00

58 lines
2.1 KiB
Diff

From 4e432e530db0056450fbc4a3cee793f16adc39a7 Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Tue, 8 Oct 2024 23:58:41 +0100
Subject: [PATCH] net: phy: populate host_interfaces when attaching PHY
Use bitmask of interfaces supported by the MAC for the PHY to choose
from if the declared interface mode is among those using a single pair
of SerDes lanes.
This will allow 2500Base-T PHYs to switch to SGMII on most hosts, which
results in half-duplex being supported in case the MAC supports them.
Without this change, 2500Base-T PHYs will always operate in 2500Base-X
mode with rate-matching, which is not only wasteful in terms of energy
consumption, but also limits the supported interface modes to
full-duplex only.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
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
@@ -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 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);
+
ret = phy_attach_direct(pl->netdev, phy_dev, flags,
pl->link_interface);
phy_device_free(phy_dev);