[PATCH net-next v1] net: stmmac: xgmac: increase length limit of descriptor ring

[Furong Xu]

DWXGMAC CORE supports a ring length of 65536 descriptors, bump max length
from 1024 to 65536

Signed-off-by: Furong Xu <0x1207 at gmail.com>
---
 .../net/ethernet/stmicro/stmmac/dwxgmac2.h    |  2 ++
 .../ethernet/stmicro/stmmac/stmmac_ethtool.c  | 24 +++++++++++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
index 6a2c7d22df1e..264f4f876c74 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
@@ -11,6 +11,8 @@
 
 /* Misc */
 #define XGMAC_JUMBO_LEN			16368
+#define XGMAC_DMA_MAX_TX_SIZE		65536
+#define XGMAC_DMA_MAX_RX_SIZE		65536
 
 /* MAC Registers */
 #define XGMAC_TX_CONFIG			0x00000000
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 18468c0228f0..3ae465c5a712 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -491,9 +491,16 @@ static void stmmac_get_ringparam(struct net_device *netdev,
 				 struct netlink_ext_ack *extack)
 {
 	struct stmmac_priv *priv = netdev_priv(netdev);
+	u32 dma_max_rx_size = DMA_MAX_RX_SIZE;
+	u32 dma_max_tx_size = DMA_MAX_TX_SIZE;
 
-	ring->rx_max_pending = DMA_MAX_RX_SIZE;
-	ring->tx_max_pending = DMA_MAX_TX_SIZE;
+	if (priv->plat->has_xgmac) {
+		dma_max_rx_size = XGMAC_DMA_MAX_RX_SIZE;
+		dma_max_tx_size = XGMAC_DMA_MAX_TX_SIZE;
+	}
+
+	ring->rx_max_pending = dma_max_rx_size;
+	ring->tx_max_pending = dma_max_tx_size;
 	ring->rx_pending = priv->dma_conf.dma_rx_size;
 	ring->tx_pending = priv->dma_conf.dma_tx_size;
 }
@@ -503,12 +510,21 @@ static int stmmac_set_ringparam(struct net_device *netdev,
 				struct kernel_ethtool_ringparam *kernel_ring,
 				struct netlink_ext_ack *extack)
 {
+	struct stmmac_priv *priv = netdev_priv(netdev);
+	u32 dma_max_rx_size = DMA_MAX_RX_SIZE;
+	u32 dma_max_tx_size = DMA_MAX_TX_SIZE;
+
+	if (priv->plat->has_xgmac) {
+		dma_max_rx_size = XGMAC_DMA_MAX_RX_SIZE;
+		dma_max_tx_size = XGMAC_DMA_MAX_TX_SIZE;
+	}
+
 	if (ring->rx_mini_pending || ring->rx_jumbo_pending ||
 	    ring->rx_pending < DMA_MIN_RX_SIZE ||
-	    ring->rx_pending > DMA_MAX_RX_SIZE ||
+	    ring->rx_pending > dma_max_rx_size ||
 	    !is_power_of_2(ring->rx_pending) ||
 	    ring->tx_pending < DMA_MIN_TX_SIZE ||
-	    ring->tx_pending > DMA_MAX_TX_SIZE ||
+	    ring->tx_pending > dma_max_tx_size ||
 	    !is_power_of_2(ring->tx_pending))
 		return -EINVAL;
 
-- 
2.34.1