diff mbox series

[5.10.y-cip,19/61] ravb: Remove the macros NUM_TX_DESC_GEN[23]

Message ID 20220110122331.24114-20-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State Accepted
Delegated to: Pavel Machek
Headers show
Series Add Ethernet support to RZ/G2L | expand

Commit Message

Lad Prabhakar Jan. 10, 2022, 12:22 p.m. UTC
From: Biju Das <biju.das.jz@bp.renesas.com>

commit c81d894226b94439c543e9cfac406c8024172fd7 upstream.

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>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb.h      | 4 ----
 drivers/net/ethernet/renesas/ravb_main.c | 8 ++++++--
 2 files changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 3d87fb40b5c8..a0e19a45b2a0 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -957,10 +957,6 @@  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 b16c179ba44c..a8007c5cdd35 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2158,8 +2158,12 @@  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;