net: phylink: simplify how SFP PHYs are attached

There are a few issues with how SFP PHYs are attached:

a) The phylink_sfp_connect_phy() and phylink_sfp_config_phy() code
   validates the configuration three times:

1. To discover the support/advertising masks that the PHY/PCS/MAC
   can support in order to select an interface.
2. To validate the selected interface.
3. When the PHY is brought up after being attached, another validation
   is done.

   This is needlessly complex.

b) The configuration is set prior to the PHY being attached, which
   means we don't have the PHY available in phylink_major_config()
   for phylink_pcs_neg_mode() to make decisions upon.

We have already added an extra step to validate the selected interface,
so we can now move the attachment and bringup of the PHY earlier,
inside phylink_sfp_config_phy(). This results in the validation at
step 2 above becoming entirely unnecessary, so remove that too.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

1 files changed, 14 insertions, 29 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 3755c69514c8..eba80ad73bf2 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -3314,10 +3314,8 @@ 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);
@@ -3338,20 +3336,21 @@ static int phylink_sfp_config_phy(struct phylink *pl, u8 mode,
 		return ret;
 	}
 
-	iface = phylink_sfp_select_interface(pl, config.advertising);
-	if (iface == PHY_INTERFACE_MODE_NA)
+	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;
 	}
 
@@ -3509,7 +3508,6 @@ 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;
 
@@ -3532,20 +3530,7 @@ 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)