Merge branch 'pcs-xpcs-cleanups'

Serge Semin says:

====================
net: pcs: xpcs: Cleanups before adding MMIO dev support

As stated in the subject this series is a short prequel before submitting
the main patches adding the memory-mapped DW XPCS support to the DW XPCS
and DW *MAC (STMMAC) drivers. Originally it was a part of the bigger
patchset (see the changelog v2 link below) but was detached to a
preparation set to shrink down the main series thus simplifying it'
review.

The patchset' content is straightforward: drop the redundant sentinel
entry and the header files; return EINVAL errno from the soft-reset method
and make sure that the interface validation method return EINVAL straight
away if the requested interface isn't supported by the XPCS device
instance. All of these changes are required to simplify the changes being
introduced a bit later in the framework of the memory-mapped DW XPCS
support patches.

Link: https://lore.kernel.org/netdev/20231205103559.9605-1-fancer.lancer@gmail.com
Changelog v2:
- Move the preparation patches to a separate series.
- Simplify the commit messages (@Russell, @Vladimir).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/pcs/pcs-xpcs.c

@@ -10,7 +10,7 @@
 #include <linux/pcs/pcs-xpcs.h>
 #include <linux/mdio.h>
 #include <linux/phylink.h>
-#include <linux/workqueue.h>
+
 #include "pcs-xpcs.h"
 
 #define phylink_pcs_to_xpcs(pl_pcs) \
@@ -130,7 +130,6 @@ static const phy_interface_t xpcs_1000basex_interfaces[] = {
 
 static const phy_interface_t xpcs_2500basex_interfaces[] = {
 	PHY_INTERFACE_MODE_2500BASEX,
-	PHY_INTERFACE_MODE_MAX,
 };
 
 enum {
@@ -293,7 +292,7 @@ static int xpcs_soft_reset(struct dw_xpcs *xpcs,
 		dev = MDIO_MMD_VEND2;
 		break;
 	default:
-		return -1;
+		return -EINVAL;
 	}
 
 	ret = xpcs_write(xpcs, dev, MDIO_CTRL1, MDIO_CTRL1_RESET);
@@ -614,14 +613,15 @@ static int xpcs_validate(struct phylink_pcs *pcs, unsigned long *supported,
 
 	xpcs = phylink_pcs_to_xpcs(pcs);
 	compat = xpcs_find_compat(xpcs->id, state->interface);
+	if (!compat)
+		return -EINVAL;
 
 	/* Populate the supported link modes for this PHY interface type.
 	 * FIXME: what about the port modes and autoneg bit? This masks
 	 * all those away.
 	 */
-	if (compat)
-		for (i = 0; compat->supported[i] != __ETHTOOL_LINK_MODE_MASK_NBITS; i++)
-			set_bit(compat->supported[i], xpcs_supported);
+	for (i = 0; compat->supported[i] != __ETHTOOL_LINK_MODE_MASK_NBITS; i++)
+		set_bit(compat->supported[i], xpcs_supported);
 
 	linkmode_and(supported, supported, xpcs_supported);
 
@@ -636,8 +636,7 @@ void xpcs_get_interfaces(struct dw_xpcs *xpcs, unsigned long *interfaces)
 		const struct xpcs_compat *compat = &xpcs->id->compat[i];
 
 		for (j = 0; j < compat->num_interfaces; j++)
-			if (compat->interface[j] < PHY_INTERFACE_MODE_MAX)
-				__set_bit(compat->interface[j], interfaces);
+			__set_bit(compat->interface[j], interfaces);
 	}
 }
 EXPORT_SYMBOL_GPL(xpcs_get_interfaces);
@@ -891,7 +890,7 @@ int xpcs_do_config(struct dw_xpcs *xpcs, phy_interface_t interface,
 			return ret;
 		break;
 	default:
-		return -1;
+		return -EINVAL;
 	}
 
 	if (compat->pma_config) {