/**************************************************************************
ETH_TRANSMIT - Transmit a frame
***************************************************************************/
static char padmap[] = {
0, 3, 2, 1};

static void t595_transmit(
struct nic *nic,
const char *d, /* Destination */
unsigned int t, /* Type */
unsigned int s, /* size */
const char *p) /* Packet */
{
register int len;
int pad;
int status;

#ifdef EDEBUG
printf("{l=%d,t=%hX}",s+ETH_HLEN,t);
#endif

/* swap bytes of type */
t= htons(t);

len=s+ETH_HLEN; /* actual length of packet */
pad = padmap[len & 3];

/*
* The 3c595 automatically pads short packets to minimum ethernet length,
* but we drop packets that are too large. Perhaps we should truncate
* them instead?
*/
if (len + pad > ETH_FRAME_LEN) {
return;
}

/* drop acknowledgements */
while(( status=inb(BASE + VX_W1_TX_STATUS) )& TXS_COMPLETE ) {
if(status & (TXS_UNDERRUN|TXS_MAX_COLLISION|TXS_STATUS_OVERFLOW)) {
outw(TX_RESET, BASE + VX_COMMAND);
outw(TX_ENABLE, BASE + VX_COMMAND);
}

outb(0x0, BASE + VX_W1_TX_STATUS);
}

while (inw(BASE + VX_W1_FREE_TX) < len + pad + 4) {
/* no room in FIFO */
}

outw(len, BASE + VX_W1_TX_PIO_WR_1);
outw(0x0, BASE + VX_W1_TX_PIO_WR_1); /* Second dword meaningless */

/* write packet */
outsw(BASE + VX_W1_TX_PIO_WR_1, d, ETH_ALEN/2);
outsw(BASE + VX_W1_TX_PIO_WR_1, nic->node_addr, ETH_ALEN/2);
outw(t, BASE + VX_W1_TX_PIO_WR_1);
outsw(BASE + VX_W1_TX_PIO_WR_1, p, s / 2);
if (s & 1)
outb(*(p+s - 1), BASE + VX_W1_TX_PIO_WR_1);

while (pad--)
outb(0, BASE + VX_W1_TX_PIO_WR_1); /* Padding */

        /* wait for Tx complete */
        while((inw(BASE + VX_STATUS) & S_COMMAND_IN_PROGRESS) != 0)
                ;
}

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