pcnet: enable the NOUFLO feature

[karo-tx-uboot.git] / drivers / net / pcnet.c

diff --git a/drivers/net/pcnet.c b/drivers/net/pcnet.c
index 7b87660281751bcfdccf2492c308a21b790a148a..5b248bee431ad4caf287bf0550aab8b777255174 100644 (file)
--- a/drivers/net/pcnet.c
+++ b/drivers/net/pcnet.c
@@ -311,6 +311,21 @@ static int pcnet_init(struct eth_device *dev, bd_t *bis)
        val |= 0x20;
        pcnet_write_bcr(dev, 32, val);
 
+       /*
+        * Enable NOUFLO on supported controllers, with the transmit
+        * start point set to the full packet. This will cause entire
+        * packets to be buffered by the ethernet controller before
+        * transmission, eliminating underflows which are common on
+        * slower devices. Controllers which do not support NOUFLO will
+        * simply be left with a larger transmit FIFO threshold.
+        */
+       val = pcnet_read_bcr(dev, 18);
+       val |= 1 << 11;
+       pcnet_write_bcr(dev, 18, val);
+       val = pcnet_read_csr(dev, 80);
+       val |= 0x3 << 10;
+       pcnet_write_csr(dev, 80, val);
+
        /*
         * We only maintain one structure because the drivers will never
         * be used concurrently. In 32bit mode the RX and TX ring entries