net: of_get_phy_mode: Change API to solve int/unit warnings

Before this change of_get_phy_mode() returned an enum,
phy_interface_t. On error, -ENODEV etc, is returned. If the result of
the function is stored in a variable of type phy_interface_t, and the
compiler has decided to represent this as an unsigned int, comparision
with -ENODEV etc, is a signed vs unsigned comparision.

Fix this problem by changing the API. Make the function return an
error, or 0 on success, and pass a pointer, of type phy_interface_t,
where the phy mode should be stored.

v2:
Return with *interface set to PHY_INTERFACE_MODE_NA on error.
Add error checks to all users of of_get_phy_mode()
Fixup a few reverse christmas tree errors
Fixup a few slightly malformed reverse christmas trees

v3:
Fix 0-day reported errors.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 13 insertions, 7 deletions

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index bd6129db6417..c6b87ce2b0cc 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -361,8 +361,8 @@ struct phy_device *of_phy_get_and_connect(struct net_device *dev,
 	struct phy_device *phy;
 	int ret;
 
-	iface = of_get_phy_mode(np);
-	if ((int)iface < 0)
+	ret = of_get_phy_mode(np, &iface);
+	if (ret)
 		return NULL;
 	if (of_phy_is_fixed_link(np)) {
 		ret = of_phy_register_fixed_link(np);
diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c
index b02734aff8c1..6e411821583e 100644
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -15,16 +15,20 @@
 /**
  * of_get_phy_mode - Get phy mode for given device_node
  * @np:	Pointer to the given device_node
+ * @interface: Pointer to the result
  *
  * The function gets phy interface string from property 'phy-mode' or
- * 'phy-connection-type', and return its index in phy_modes table, or errno in
- * error case.
+ * 'phy-connection-type'. The index in phy_modes table is set in
+ * interface and 0 returned. In case of error interface is set to
+ * PHY_INTERFACE_MODE_NA and an errno is returned, e.g. -ENODEV.
  */
-int of_get_phy_mode(struct device_node *np)
+int of_get_phy_mode(struct device_node *np, phy_interface_t *interface)
 {
 	const char *pm;
 	int err, i;
 
+	*interface = PHY_INTERFACE_MODE_NA;
+
 	err = of_property_read_string(np, "phy-mode", &pm);
 	if (err < 0)
 		err = of_property_read_string(np, "phy-connection-type", &pm);
@@ -32,8 +36,10 @@ int of_get_phy_mode(struct device_node *np)
 		return err;
 
 	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
-		if (!strcasecmp(pm, phy_modes(i)))
-			return i;
+		if (!strcasecmp(pm, phy_modes(i))) {
+			*interface = i;
+			return 0;
+		}
 
 	return -ENODEV;
 }