net: ks8851: Receive one packet per recv call

Instead of reading out the entire FIFO and possibly overwriting U-Boot
memory, read out one packet per recv call, pass it to U-Boot network
stack, and repeat. It is however necessary to cache RXFC value, because
reading that one out clears it.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/drivers/net/ks8851_mll.c b/drivers/net/ks8851_mll.c
index 2d41e5b9c7c23e12651c17dc2be3961565a7aaf0..2424e4297e47ea95f5a1b4b510f14abe326a2706 100644 (file)
--- a/drivers/net/ks8851_mll.c
+++ b/drivers/net/ks8851_mll.c
@@ -32,6 +32,7 @@ struct ks_net {
        phys_addr_t             iobase;
        int                     bus_width;
        u16                     sharedbus;
+       u16                     rxfc;
        u8                      extra_byte;
 };
 
@@ -225,33 +226,31 @@ static inline void ks_read_qmu(struct ks_net *ks, u16 *buf, u32 len)
        ks_wrreg16(ks, KS_RXQCR, RXQCR_CMD_CNTL);
 }
 
-static void ks_rcv(struct ks_net *ks, uchar **pv_data)
+static int ks_rcv(struct ks_net *ks, uchar *data)
 {
-       unsigned int frame_cnt;
        u16 sts, len;
-       int i;
-
-       frame_cnt = ks_rdreg16(ks, KS_RXFCTR) >> 8;
-
-       /* read all header information */
-       for (i = 0; i < frame_cnt; i++) {
-               /* Checking Received packet status */
-               sts = ks_rdreg16(ks, KS_RXFHSR);
-               /* Get packet len from hardware */
-               len = ks_rdreg16(ks, KS_RXFHBCR);
-
-               if ((sts & RXFSHR_RXFV) && len && (len < RX_BUF_SIZE)) {
-                       /* read data block including CRC 4 bytes */
-                       ks_read_qmu(ks, (u16 *)(*pv_data), len);
-
-                       /* net_rx_packets buffer size is ok (*pv_data) */
-                       net_process_received_packet(*pv_data, len);
-                       pv_data++;
-               } else {
-                       ks_wrreg16(ks, KS_RXQCR, RXQCR_CMD_CNTL | RXQCR_RRXEF);
-                       printf(DRIVERNAME ": bad packet\n");
-               }
+
+       if (!ks->rxfc)
+               ks->rxfc = ks_rdreg16(ks, KS_RXFCTR) >> 8;
+
+       if (!ks->rxfc)
+               return 0;
+
+       /* Checking Received packet status */
+       sts = ks_rdreg16(ks, KS_RXFHSR);
+       /* Get packet len from hardware */
+       len = ks_rdreg16(ks, KS_RXFHBCR);
+
+       if ((sts & RXFSHR_RXFV) && len && (len < RX_BUF_SIZE)) {
+               /* read data block including CRC 4 bytes */
+               ks_read_qmu(ks, (u16 *)data, len);
+               ks->rxfc--;
+               return len - 4;
        }
+
+       ks_wrreg16(ks, KS_RXQCR, RXQCR_CMD_CNTL | RXQCR_RRXEF);
+       printf(DRIVERNAME ": bad packet\n");
+       return 0;
 }
 
 /*
@@ -407,6 +406,8 @@ static int ks8851_mll_init_common(struct ks_net *ks)
        /* Configure the PHY, initialize the link state */
        ks8851_mll_phy_configure(ks);
 
+       ks->rxfc = 0;
+
        /* Turn on Tx + Rx */
        ks8851_mll_enable(ks);
 
@@ -466,16 +467,17 @@ static void ks8851_mll_halt_common(struct ks_net *ks)
  * needs to be enough to prevent a packet being discarded while
  * we are processing the previous one.
  */
-static int ks8851_mll_recv_common(struct ks_net *ks, uchar **data)
+static int ks8851_mll_recv_common(struct ks_net *ks, uchar *data)
 {
        u16 status;
+       int ret = 0;
 
        status = ks_rdreg16(ks, KS_ISR);
 
        ks_wrreg16(ks, KS_ISR, status);
 
-       if (status & IRQ_RXI)
-               ks_rcv(ks, data);
+       if (ks->rxfc || (status & IRQ_RXI))
+               ret = ks_rcv(ks, data);
 
        if (status & IRQ_LDI) {
                u16 pmecr = ks_rdreg16(ks, KS_PMECR);
@@ -484,7 +486,7 @@ static int ks8851_mll_recv_common(struct ks_net *ks, uchar **data)
                ks_wrreg16(ks, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
        }
 
-       return 0;
+       return ret;
 }
 
 static void ks8851_mll_write_hwaddr_common(struct ks_net *ks, u8 enetaddr[6])
@@ -524,8 +526,13 @@ static int ks8851_mll_send(struct eth_device *dev, void *packet, int length)
 static int ks8851_mll_recv(struct eth_device *dev)
 {
        struct ks_net *ks = container_of(dev, struct ks_net, dev);
+       int ret;
+
+       ret = ks8851_mll_recv_common(ks, net_rx_packets[0]);
+       if (ret)
+               net_process_received_packet(net_rx_packets[0], ret);
 
-       return ks8851_mll_recv_common(ks, (uchar **)net_rx_packets);
+       return ret;
 }
 
 static int ks8851_mll_write_hwaddr(struct eth_device *dev)