[U-Boot] [PATCH] Bugfix: mpc512x_fec MII accesses fail after ethernet transfers

[Thomas Dörfler]

The mpc512x FEC network driver resets the FEC before transferring
packets. With this reset, the FEC clears the previous setting of MII
transfer speed. This patch ensures, that it is set again to a reasonable
value after a FEC reset.

Signed-off-by: Thomas Doerfler <Thomas.Doerfler at embedded-brains.de>
--
diff --git a/drivers/net/mpc512x_fec.c b/drivers/net/mpc512x_fec.c
index fb2c19a..f3d76ba 100644
--- a/drivers/net/mpc512x_fec.c
+++ b/drivers/net/mpc512x_fec.c
@@ -446,6 +446,19 @@ static void mpc512x_fec_halt (struct eth_device *dev)
         * wait at least 16 clock cycles
         */
        udelay (10);
+       /*
+        * NOTE: reset will also clear the MII speed register
+        * we should reinitialize it ASAP
+        */
+       if (fec->xcv_type != SEVENWIRE) {
+               /*
+                * Set MII_SPEED = (1/(mii_speed * 2)) * System Clock
+                * and do not drop the Preamble.
+                */
+               fec->eth->mii_speed = ((((gd->ips_clk / 1000000) / 5)
+                                       + 1)
+                                      << 1);
+       }
 #if (DEBUG & 0x3)
        printf ("Ethernet task stopped\n");
 #endif
-- 

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