netdev: bfin_mac: document TE setting in RMII modes

The current code sometimes generates build warnings due to how it checks
the silicon revision, so clean it up and properly document things.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
index 22abfb3..68d45ba 100644 (file)
--- a/drivers/net/bfin_mac.c
+++ b/drivers/net/bfin_mac.c
@@ -1237,8 +1237,17 @@ static int bfin_mac_enable(struct phy_device *phydev)
 
        if (phydev->interface == PHY_INTERFACE_MODE_RMII) {
                opmode |= RMII; /* For Now only 100MBit are supported */
-#if (defined(CONFIG_BF537) || defined(CONFIG_BF536)) && CONFIG_BF_REV_0_2
-               opmode |= TE;
+#if defined(CONFIG_BF537) || defined(CONFIG_BF536)
+               if (__SILICON_REVISION__ < 3) {
+                       /*
+                        * This isn't publicly documented (fun times!), but in
+                        * silicon <=0.2, the RX and TX pins are clocked together.
+                        * So in order to recv, we must enable the transmit side
+                        * as well.  This will cause a spurious TX interrupt too,
+                        * but we can easily consume that.
+                        */
+                       opmode |= TE;
+               }
 #endif
        }