[PATCH] (2/3) 8139too -- configurable receive ring

[Stephen Hemminger <shemminger@xxxxxxxx>]

For net-drivers-2.5-exp:  Make the receive window configurable and go
back to the original 32K by default.

diff -Nru a/drivers/net/8139too.c b/drivers/net/8139too.c
--- a/drivers/net/8139too.c     Wed Nov 19 14:34:02 2003
+++ b/drivers/net/8139too.c     Wed Nov 19 14:34:02 2003
@@ -128,13 +128,6 @@
 #define USE_IO_OPS 1
 #endif
 
-/* use a 16K rx ring buffer instead of the default 64K */
-#if defined(CONFIG_SH_DREAMCAST) || defined(CONFIG_EMBEDDED)
-#define USE_BUF16K 1
-#else
-#define USE_BUF64K 1
-#endif
-
 /* define to 1 to enable copious debugging info */
 #undef RTL8139_DEBUG
 
@@ -173,20 +166,12 @@
 /* bitmapped message enable number */
 static int debug = -1;
 
-/* Size of the in-memory receive ring. */
-/* 0==8K, 1==16K, 2==32K, 3==64K */
-#ifdef USE_BUF16K
-#define RX_BUF_LEN_IDX 1
-#elif defined(USE_BUF32K)
-#define RX_BUF_LEN_IDX 2
-#else
-#define RX_BUF_LEN_IDX 3
-#endif
-
-#define RX_BUF_LEN     (8192 << RX_BUF_LEN_IDX)
+/* Ring size is now a config option */
+#define RX_BUF_LEN     (8192 << CONFIG_8139_RXBUF_IDX)
 #define RX_BUF_PAD     16
 #define RX_BUF_WRAP_PAD 2048 /* spare padding to handle lack of packet wrap */
-#ifdef USE_BUF64K
+
+#if RX_BUF_LEN == 65536
 #define RX_BUF_TOT_LEN RX_BUF_LEN
 #else
 #define RX_BUF_TOT_LEN (RX_BUF_LEN + RX_BUF_PAD + RX_BUF_WRAP_PAD)
@@ -703,23 +688,28 @@
        PCIErr | PCSTimeout | RxUnderrun |
        TxErr | TxOK | RxErr ;
 
-#ifdef USE_BUF16K 
+#if CONFIG_8139_RXBUF_IDX == 0
+static const unsigned int rtl8139_rx_config =
+       RxCfgRcv8K | RxNoWrap |
+       (RX_FIFO_THRESH << RxCfgFIFOShift) |
+       (RX_DMA_BURST << RxCfgDMAShift);
+#elif CONFIG_8139_RXBUF_IDX == 1
 static const unsigned int rtl8139_rx_config =
        RxCfgRcv16K | RxNoWrap |
        (RX_FIFO_THRESH << RxCfgFIFOShift) |
        (RX_DMA_BURST << RxCfgDMAShift);
-#elif defined(USE_BUF32K)
+#elif CONFIG_8139_RXBUF_IDX == 2
 static const unsigned int rtl8139_rx_config =
        RxCfgRcv32K | RxNoWrap |
        (RX_FIFO_THRESH << RxCfgFIFOShift) |
        (RX_DMA_BURST << RxCfgDMAShift);
-#elif defined(USE_BUF64K)
+#elif CONFIG_8139_RXBUF_IDX == 3
 static const unsigned int rtl8139_rx_config =
        RxCfgRcv64K |
        (RX_FIFO_THRESH << RxCfgFIFOShift) |
        (RX_DMA_BURST << RxCfgDMAShift);
 #else
-#error "Need to define receive buffer window"
+#error "Invalid configuration for 8139_RXBUF_IDX"
 #endif
 
 static const unsigned int rtl8139_tx_config =
@@ -1916,26 +1906,26 @@
 #endif
 }
 
+#if CONFIG_8139_RXBUF_IDX == 3
 static __inline__ void wrap_copy(struct sk_buff *skb, const unsigned char 
*ring,
                                 u32 offset, unsigned int size)
 {
-#ifdef USE_BUF64K
        u32 left = RX_BUF_LEN - offset;
 
        if (size > left) {
                memcpy(skb->data, ring + offset, left);
                memcpy(skb->data+left, ring, size - left);
        } else
-#endif
                memcpy(skb->data, ring + offset, size);
 }
+#endif
 
 static int rtl8139_rx(struct net_device *dev, struct rtl8139_private *tp,
                      int budget)
 {
        void *ioaddr = tp->mmio_addr;
        int received = 0;
-       const unsigned char *rx_ring = tp->rx_ring;
+       unsigned char *rx_ring = tp->rx_ring;
        unsigned int cur_rx = tp->cur_rx;
 
        DPRINTK ("%s: In rtl8139_rx(), current %4.4x BufAddr %4.4x,"
@@ -2002,8 +1992,11 @@
                if (likely(skb)) {
                        skb->dev = dev;
                        skb_reserve (skb, 2);   /* 16 byte align the IP fields. 
*/
+#if CONFIG_8139_RXBUF_IDX == 3
                        wrap_copy(skb, rx_ring, ring_offset+4, pkt_size);
-
+#else
+                       eth_copy_and_sum (skb, &rx_ring[ring_offset + 4], 
pkt_size, 0);
+#endif
                        skb_put (skb, pkt_size);
 
                        skb->protocol = eth_type_trans (skb, dev);
diff -Nru a/drivers/net/Kconfig b/drivers/net/Kconfig
--- a/drivers/net/Kconfig       Wed Nov 19 14:34:02 2003
+++ b/drivers/net/Kconfig       Wed Nov 19 14:34:02 2003
@@ -1564,6 +1564,24 @@
          experience problems, you can enable this option to restore the
          old RX-reset behavior.  If unsure, say N.
 
+config 8139_RXBUF_IDX
+       int "Receive ring size (0 => 8K, 1 => 16K, 2 => 32K, 3 => 64K)"
+       depends on 8139TOO
+       range 0 3
+       default 1 if EMBEDDED || SH_DREAMCAST
+       default 2
+       help
+          The 8139too driver has a fixed area of memory for receiving data.
+          The default value is adequate for most systems. The 64KB 
+          ring size has hardware issues that may cause problems.
+          Values:
+               0  => 8 KB 
+               1  => 16 KB embedded systems
+               2  => 32 KB default for most systems
+               3  => 64 KB 
+          If unsure, use the default 2.
+
+
 config SIS900
        tristate "SiS 900/7016 PCI Fast Ethernet Adapter support"
        depends on NET_PCI && PCI