Merge branch 'net-phylink-simplify-sfp-phy-attachment'

Russell King says:

====================
net: phylink: simplify SFP PHY attachment

These two patches simplify how we attach SFP PHYs.

The first patch notices that at the two sites where we call
sfp_select_interface(), if that fails, we always print the same error.
Move this into its own function.

The second patch adds an additional level of validation, checking that
the returned interface is one that is supported by the MAC/PCS.

The last patch simplifies how SFP PHYs are attached, reducing the
number of times that we do validation in this path.
====================

Link: https://patch.msgid.link/Zxj8_clRmDA_G7uH@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 42 insertions, 41 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 20c227e22993..6ca7ea970f51 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2408,6 +2408,32 @@ int phylink_ethtool_set_wol(struct phylink *pl, struct ethtool_wolinfo *wol)
 }
 EXPORT_SYMBOL_GPL(phylink_ethtool_set_wol);
 
+static phy_interface_t phylink_sfp_select_interface(struct phylink *pl,
+						const unsigned long *link_modes)
+{
+	phy_interface_t interface;
+
+	interface = sfp_select_interface(pl->sfp_bus, link_modes);
+	if (interface == PHY_INTERFACE_MODE_NA) {
+		phylink_err(pl,
+			    "selection of interface failed, advertisement %*pb\n",
+			    __ETHTOOL_LINK_MODE_MASK_NBITS,
+			    link_modes);
+		return interface;
+	}
+
+	if (!test_bit(interface, pl->config->supported_interfaces)) {
+		phylink_err(pl,
+			    "selection of interface failed, SFP selected %s (%u) but MAC supports %*pbl\n",
+			    phy_modes(interface), interface,
+			    (int)PHY_INTERFACE_MODE_MAX,
+			    pl->config->supported_interfaces);
+		return PHY_INTERFACE_MODE_NA;
+	}
+
+	return interface;
+}
+
 static void phylink_merge_link_mode(unsigned long *dst, const unsigned long *b)
 {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask);
@@ -2590,15 +2616,10 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
 	 * link can be configured correctly.
 	 */
 	if (pl->sfp_bus) {
-		config.interface = sfp_select_interface(pl->sfp_bus,
+		config.interface = phylink_sfp_select_interface(pl,
 							config.advertising);
-		if (config.interface == PHY_INTERFACE_MODE_NA) {
-			phylink_err(pl,
-				    "selection of interface failed, advertisement %*pb\n",
-				    __ETHTOOL_LINK_MODE_MASK_NBITS,
-				    config.advertising);
+		if (config.interface == PHY_INTERFACE_MODE_NA)
 			return -EINVAL;
-		}
 
 		/* Revalidate with the selected interface */
 		linkmode_copy(support, pl->supported);
@@ -3203,10 +3224,8 @@ static void phylink_sfp_set_config(struct phylink *pl, u8 mode,
 static int phylink_sfp_config_phy(struct phylink *pl, u8 mode,
 				  struct phy_device *phy)
 {
-	__ETHTOOL_DECLARE_LINK_MODE_MASK(support1);
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(support);
 	struct phylink_link_state config;
-	phy_interface_t iface;
 	int ret;
 
 	linkmode_copy(support, phy->supported);
@@ -3227,24 +3246,21 @@ static int phylink_sfp_config_phy(struct phylink *pl, u8 mode,
 		return ret;
 	}
 
-	iface = sfp_select_interface(pl->sfp_bus, config.advertising);
-	if (iface == PHY_INTERFACE_MODE_NA) {
-		phylink_err(pl,
-			    "selection of interface failed, advertisement %*pb\n",
-			    __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising);
+	config.interface = phylink_sfp_select_interface(pl, config.advertising);
+	if (config.interface == PHY_INTERFACE_MODE_NA)
 		return -EINVAL;
-	}
 
-	config.interface = iface;
-	linkmode_copy(support1, support);
-	ret = phylink_validate(pl, support1, &config);
-	if (ret) {
-		phylink_err(pl,
-			    "validation of %s/%s with support %*pb failed: %pe\n",
-			    phylink_an_mode_str(mode),
-			    phy_modes(config.interface),
-			    __ETHTOOL_LINK_MODE_MASK_NBITS, support,
-			    ERR_PTR(ret));
+	/* Attach the PHY so that the PHY is present when we do the major
+	 * configuration step.
+	 */
+	ret = phylink_attach_phy(pl, phy, config.interface);
+	if (ret < 0)
+		return ret;
+
+	/* This will validate the configuration for us. */
+	ret = phylink_bringup_phy(pl, phy, config.interface);
+	if (ret < 0) {
+		phy_detach(phy);
 		return ret;
 	}
 
@@ -3402,9 +3418,7 @@ static bool phylink_phy_no_inband(struct phy_device *phy)
 static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
 {
 	struct phylink *pl = upstream;
-	phy_interface_t interface;
 	u8 mode;
-	int ret;
 
 	/*
 	 * This is the new way of dealing with flow control for PHYs,
@@ -3425,20 +3439,7 @@ static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
 			  pl->config->supported_interfaces);
 
 	/* Do the initial configuration */
-	ret = phylink_sfp_config_phy(pl, mode, phy);
-	if (ret < 0)
-		return ret;
-
-	interface = pl->link_config.interface;
-	ret = phylink_attach_phy(pl, phy, interface);
-	if (ret < 0)
-		return ret;
-
-	ret = phylink_bringup_phy(pl, phy, interface);
-	if (ret)
-		phy_detach(phy);
-
-	return ret;
+	return phylink_sfp_config_phy(pl, mode, phy);
 }
 
 static void phylink_sfp_disconnect_phy(void *upstream,