stmmac: prefetch all dma_erx when use extend_desc

This patch is to prefetch, in the stmmac_rx, the whole
dma_erx descriptor in case of using the extended descriptors.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 8ba0532..71b6485 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2006,7 +2006,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit)
 #endif
        while (count < limit) {
                int status;
-               struct dma_desc *p, *p_next;
+               struct dma_desc *p;
 
                if (priv->extend_desc)
                        p = (struct dma_desc *)(priv->dma_erx + entry);
@@ -2020,12 +2020,9 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit)
 
                next_entry = (++priv->cur_rx) % rxsize;
                if (priv->extend_desc)
-                       p_next = (struct dma_desc *)(priv->dma_erx +
-                                                    next_entry);
+                       prefetch(priv->dma_erx + next_entry);
                else
-                       p_next = priv->dma_rx + next_entry;
-
-               prefetch(p_next);
+                       prefetch(priv->dma_rx + next_entry);
 
                /* read the status of the incoming frame */
                status = priv->hw->desc->rx_status(&priv->dev->stats,