enc28j60: reduce the number of spi transfers in enc28j60_set_bank()

[firefly-linux-kernel-4.4.55.git] / drivers / net / enc28j60.c

diff --git a/drivers/net/enc28j60.c b/drivers/net/enc28j60.c
index 32c19790d0135f921ab8f89d90909a04fcffa057..b0ef46c51a9d556069c38ed97d0cdf3086555d6f 100644 (file)
--- a/drivers/net/enc28j60.c
+++ b/drivers/net/enc28j60.c
@@ -196,16 +196,32 @@ static void enc28j60_soft_reset(struct enc28j60_net *priv)
  */
 static void enc28j60_set_bank(struct enc28j60_net *priv, u8 addr)
 {
-       if ((addr & BANK_MASK) != priv->bank) {
-               u8 b = (addr & BANK_MASK) >> 5;
+       u8 b = (addr & BANK_MASK) >> 5;
 
-               if (b != (ECON1_BSEL1 | ECON1_BSEL0))
+       /* These registers (EIE, EIR, ESTAT, ECON2, ECON1)
+        * are present in all banks, no need to switch bank
+        */
+       if (addr >= EIE && addr <= ECON1)
+               return;
+
+       /* Clear or set each bank selection bit as needed */
+       if ((b & ECON1_BSEL0) != (priv->bank & ECON1_BSEL0)) {
+               if (b & ECON1_BSEL0)
+                       spi_write_op(priv, ENC28J60_BIT_FIELD_SET, ECON1,
+                                       ECON1_BSEL0);
+               else
+                       spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, ECON1,
+                                       ECON1_BSEL0);
+       }
+       if ((b & ECON1_BSEL1) != (priv->bank & ECON1_BSEL1)) {
+               if (b & ECON1_BSEL1)
+                       spi_write_op(priv, ENC28J60_BIT_FIELD_SET, ECON1,
+                                       ECON1_BSEL1);
+               else
                        spi_write_op(priv, ENC28J60_BIT_FIELD_CLR, ECON1,
-                                    ECON1_BSEL1 | ECON1_BSEL0);
-               if (b != 0)
-                       spi_write_op(priv, ENC28J60_BIT_FIELD_SET, ECON1, b);
-               priv->bank = (addr & BANK_MASK);
+                                       ECON1_BSEL1);
        }
+       priv->bank = b;
 }
 
 /*
@@ -566,6 +582,17 @@ static u16 erxrdpt_workaround(u16 next_packet_ptr, u16 start, u16 end)
        return erxrdpt;
 }
 
+/*
+ * Calculate wrap around when reading beyond the end of the RX buffer
+ */
+static u16 rx_packet_start(u16 ptr)
+{
+       if (ptr + RSV_SIZE > RXEND_INIT)
+               return (ptr + RSV_SIZE) - (RXEND_INIT - RXSTART_INIT + 1);
+       else
+               return ptr + RSV_SIZE;
+}
+
 static void nolock_rxfifo_init(struct enc28j60_net *priv, u16 start, u16 end)
 {
        u16 erxrdpt;
@@ -936,15 +963,16 @@ static void enc28j60_hw_rx(struct net_device *ndev)
                        skb->dev = ndev;
                        skb_reserve(skb, NET_IP_ALIGN);
                        /* copy the packet from the receive buffer */
-                       enc28j60_mem_read(priv, priv->next_pk_ptr + sizeof(rsv),
-                                       len, skb_put(skb, len));
+                       enc28j60_mem_read(priv,
+                               rx_packet_start(priv->next_pk_ptr),
+                               len, skb_put(skb, len));
                        if (netif_msg_pktdata(priv))
                                dump_packet(__func__, skb->len, skb->data);
                        skb->protocol = eth_type_trans(skb, ndev);
                        /* update statistics */
                        ndev->stats.rx_packets++;
                        ndev->stats.rx_bytes += len;
-                       netif_rx(skb);
+                       netif_rx_ni(skb);
                }
        }
        /*