net: phy: introduce a quirk PHY_FLAG_BROKEN_RESET

Current driver always performs a phy soft reset when connecting the phy
device, but soft reset is not always supported by a phy device, so
introduce a quirk PHY_FLAG_BROKEN_RESET to let such a phy device to skip
soft reset. This commit uses 'flags' of phy device structure to store the
quirk.

Signed-off-by: Shaohui Xie <Shaohui.Xie@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/phy/phy.c

@@ -743,6 +743,9 @@ int phy_reset(struct phy_device *phydev)
 	int timeout = 500;
 	int devad = MDIO_DEVAD_NONE;
 
+	if (phydev->flags & PHY_FLAG_BROKEN_RESET)
+		return 0;
+
 #ifdef CONFIG_PHYLIB_10G
 	/* If it's 10G, we need to issue reset through one of the MMDs */
 	if (is_10g_interface(phydev->interface)) {

include/phy.h

@@ -17,6 +17,8 @@
 
 #define PHY_MAX_ADDR 32
 
+#define PHY_FLAG_BROKEN_RESET	(1 << 0) /* soft reset not supported */
+
 #define PHY_DEFAULT_FEATURES	(SUPPORTED_Autoneg | \
 				 SUPPORTED_TP | \
 				 SUPPORTED_MII)