DSA: Enable cascading in multi-chip 6131 configuration

This patch enables the 6131 family of chips to forward DSA
packets to other switch chips.  This is needed if multiple
DSA chips are used in a device.  Without this patch the
chip will drop any DSA packets not destined for it.

This patch only enables the forwarding of DSA packets if
multiple chips are used in the switch configuration.

Signed-off-by: Barry Grussling <barry@grussling.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/mv88e6131.c b/net/dsa/mv88e6131.c
index 45f7411e90baf02fbed1642676f6448b74d024cb..9bd1061fa4ee5f6ef0b88b838c458d47603d541a 100644 (file)
--- a/net/dsa/mv88e6131.c
+++ b/net/dsa/mv88e6131.c
@@ -118,10 +118,14 @@ static int mv88e6131_setup_global(struct dsa_switch *ds)
        REG_WRITE(REG_GLOBAL, 0x1a, (dsa_upstream_port(ds) * 0x1100) | 0x00f0);
 
        /*
-        * Disable cascade port functionality, and set the switch's
+        * Disable cascade port functionality unless this device
+        * is used in a cascade configuration, and set the switch's
         * DSA device number.
         */
-       REG_WRITE(REG_GLOBAL, 0x1c, 0xe000 | (ds->index & 0x1f));
+       if (ds->dst->pd->nr_chips > 1)
+               REG_WRITE(REG_GLOBAL, 0x1c, 0xf000 | (ds->index & 0x1f));
+       else
+               REG_WRITE(REG_GLOBAL, 0x1c, 0xe000 | (ds->index & 0x1f));
 
        /*
         * Send all frames with destination addresses matching