net: Refactor full duplex flow control resolution
These 4 drivers have identical full duplex flow control resolution
functions. This patch changes them all to use one common function.
The function in question decides whether a device should enable TX and
RX flow control in a standard way (IEEE 802.3-2005 table 28B-3), so this
should also be useful for other drivers.
Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mii.h b/include/linux/mii.h
index 4a376e0..ad74858 100644
--- a/include/linux/mii.h
+++ b/include/linux/mii.h
@@ -239,5 +239,34 @@
return 0;
}
+/**
+ * mii_resolve_flowctrl_fdx
+ * @lcladv: value of MII ADVERTISE register
+ * @rmtadv: value of MII LPA register
+ *
+ * Resolve full duplex flow control as per IEEE 802.3-2005 table 28B-3
+ */
+static inline u8 mii_resolve_flowctrl_fdx(u16 lcladv, u16 rmtadv)
+{
+ u8 cap = 0;
+
+ if (lcladv & ADVERTISE_PAUSE_CAP) {
+ if (lcladv & ADVERTISE_PAUSE_ASYM) {
+ if (rmtadv & LPA_PAUSE_CAP)
+ cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
+ else if (rmtadv & LPA_PAUSE_ASYM)
+ cap = FLOW_CTRL_RX;
+ } else {
+ if (rmtadv & LPA_PAUSE_CAP)
+ cap = FLOW_CTRL_TX | FLOW_CTRL_RX;
+ }
+ } else if (lcladv & ADVERTISE_PAUSE_ASYM) {
+ if ((rmtadv & LPA_PAUSE_CAP) && (rmtadv & LPA_PAUSE_ASYM))
+ cap = FLOW_CTRL_TX;
+ }
+
+ return cap;
+}
+
#endif /* __KERNEL__ */
#endif /* __LINUX_MII_H__ */