ravb: Remove the macros NUM_TX_DESC_GEN[23]

For addressing 4 bytes alignment restriction on transmission
buffer for R-Car Gen2 we use 2 descriptors whereas it is a single
descriptor for other cases.
Replace the macros NUM_TX_DESC_GEN[23] with magic number and
add a comment to explain it.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 37ad0f8aaf3c85cafc7d237a1a09739cd27f86f4..84700a82a41c57a2414ebc2d7e4a7dbde7f95bbe 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -956,10 +956,6 @@ enum RAVB_QUEUE {
 
 #define RX_BUF_SZ      (2048 - ETH_FCS_LEN + sizeof(__sum16))
 
-/* TX descriptors per packet */
-#define NUM_TX_DESC_GEN2       2
-#define NUM_TX_DESC_GEN3       1
-
 struct ravb_tstamp_skb {
        struct list_head list;
        struct sk_buff *skb;

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 02842b980a7f88dfb4e638da2b901276195e0546..073e690ab830359bb515f7bd4f3374746bf9562c 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2160,8 +2160,12 @@ static int ravb_probe(struct platform_device *pdev)
        ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
        ndev->min_mtu = ETH_MIN_MTU;
 
-       priv->num_tx_desc = info->aligned_tx ?
-               NUM_TX_DESC_GEN2 : NUM_TX_DESC_GEN3;
+       /* FIXME: R-Car Gen2 has 4byte alignment restriction for tx buffer
+        * Use two descriptor to handle such situation. First descriptor to
+        * handle aligned data buffer and second descriptor to handle the
+        * overflow data because of alignment.
+        */
+       priv->num_tx_desc = info->aligned_tx ? 2 : 1;
 
        /* Set function */
        ndev->netdev_ops = &ravb_netdev_ops;