pasemi_mac: workaround for erratum 5971

pasemi_mac: workaround for erratum 5971

Implement workarounds for erratum 5971, where L2 hints aren't considered
properly unless the way hint is enabled on the interface. Since L2 isn't
setup to dedicate a way to headers, we need to reset the packet count
by hand so it won't run out of credits.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/pasemi_mac.c b/drivers/net/pasemi_mac.c
index 5eb5e47..c538c66 100644
--- a/drivers/net/pasemi_mac.c
+++ b/drivers/net/pasemi_mac.c
@@ -239,7 +239,9 @@
 			   PAS_DMA_RXINT_BASEU_SIZ(RX_RING_SIZE >> 3));
 
 	write_dma_reg(mac, PAS_DMA_RXINT_CFG(mac->dma_if),
-			   PAS_DMA_RXINT_CFG_DHL(2));
+			   PAS_DMA_RXINT_CFG_DHL(3) |
+			   PAS_DMA_RXINT_CFG_L2 |
+			   PAS_DMA_RXINT_CFG_LW);
 
 	ring->next_to_fill = 0;
 	ring->next_to_clean = 0;
@@ -589,6 +591,11 @@
 		n += 2;
 	}
 
+	if (n > RX_RING_SIZE) {
+		/* Errata 5971 workaround: L2 target of headers */
+		write_iob_reg(mac, PAS_IOB_COM_PKTHDRCNT, 0);
+		n &= (RX_RING_SIZE-1);
+	}
 	mac->rx->next_to_clean = n;
 	pasemi_mac_replenish_rx_ring(mac->netdev, limit-count);