net: stmmac: Fixed the condition of extend_desc for jumbo frame

This patch fixed the condition of extend_desc for jumbo frame.
There is no check routine for extend_desc in the stmmac_jumbo_frm function.
Even though extend_desc is set if dma_tx is used instead of dma_etx.
It causes kernel panic.

Signed-off-by: Byungho An <bh74.an@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c
index c9d942a5c335..1ef9d8a555aa 100644
--- a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c
+++ b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c
@@ -33,10 +33,15 @@ static unsigned int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
         struct stmmac_priv *priv = (struct stmmac_priv *)p;
         unsigned int txsize = priv->dma_tx_size;
         unsigned int entry = priv->cur_tx % txsize;
-        struct dma_desc *desc = priv->dma_tx + entry;
+        struct dma_desc *desc;
         unsigned int nopaged_len = skb_headlen(skb);
         unsigned int bmax, len;
 
+        if (priv->extend_desc)
+                desc = (struct dma_desc *)(priv->dma_etx + entry);
+        else
+                desc = priv->dma_tx + entry;
+
         if (priv->plat->enh_desc)
                 bmax = BUF_SIZE_8KiB;
         else
@@ -54,7 +59,11 @@ static unsigned int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
                                                 STMMAC_RING_MODE);
                 wmb();
                 entry = (++priv->cur_tx) % txsize;
-                desc = priv->dma_tx + entry;
+
+                if (priv->extend_desc)
+                        desc = (struct dma_desc *)(priv->dma_etx + entry);
+                else
+                        desc = priv->dma_tx + entry;
 
                 desc->des2 = dma_map_single(priv->device, skb->data + bmax,
                                             len, DMA_TO_DEVICE);