This driver supports the Arnet SYNC/570i ISA cards that is based on the

HD64570 chip. Both the 2 and 4 port cards is supported and auto detected.

Line speeds of up to 2Mbps is possible. At this speed about 85% of the
bandwidth is usable with 486DX processors.

The standard FreeBSD sppp code is used for the link level layer. The
default protocol used is PPP. The Cisco HDLC protocol can be used by
adding "link2" to the ifconfig line in /etc/sysconfig or where ever
ifconfig is run.

At the moment only the V.35 and X.21 interfaces is supported. The others
may need tweaks to the clock selection code.

Submitted by: John Hay <jhay@mikom.csir.co.za>

1 files changed, 1455 insertions, 0 deletions

diff --git a/sys/i386/isa/if_ar.c b/sys/i386/isa/if_ar.c
new file mode 100644
index 0000000..ce46405
--- /dev/null
+++ b/sys/i386/isa/if_ar.c
@@ -0,0 +1,1455 @@
+/*
+ * Copyright (c) 1995 John Hay.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by John Hay.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY John Hay ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL John Hay BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Id: if_ar.c,v 1.7 1995/11/16 20:16:34 jhay Exp $
+ */
+
+/*
+ * Programming assumptions and other issues.
+ *
+ * The descriptors of a DMA channel will fit in a 16K memory window.
+ *
+ * The buffers of a transmit DMA channel will fit in a 16K memory window.
+ *
+ * Only the ISA bus and V.35 is tested.
+ *
+ * When interface is going up, handshaking is set and it is only cleared
+ * when the interface is down'ed.
+ *
+ * There should be a way to set/reset Raw HDLC/PPP, Loopback, DCE/DTE,
+ * internal/external clock, etc.....
+ *
+ */
+
+#include "ar.h"
+#include "bpfilter.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/mbuf.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/conf.h>
+#include <sys/errno.h>
+#include <sys/malloc.h>
+
+#include <sys/syslog.h>
+#include <net/if.h>
+#include <net/if_types.h>
+#include <net/if_sppp.h>
+
+#if NBPFILTER > 0
+#include <net/bpf.h>
+#include <net/bpfdesc.h>
+#endif
+
+#include <sys/devconf.h>
+#include <machine/clock.h>
+
+#include <i386/isa/if_arregs.h>
+#include <i386/isa/ic/hd64570.h>
+
+#ifdef TRACE
+#define TRC(x)               x
+#else
+#define TRC(x)
+#endif
+
+#define TRCL(x)              x
+
+#define PPP_HEADER_LEN       4
+
+#define ARC_GET_WIN(addr)	((addr >> ARC_WIN_SHFT) & AR_WIN_MSK)
+
+#define ARC_SET_MEM(iobase,win)	outb(iobase+AR_MSCA_EN, AR_ENA_MEM | \
+				ARC_GET_WIN(win))
+#define ARC_SET_SCA(iobase,ch)	outb(iobase+AR_MSCA_EN, AR_ENA_MEM | \
+				AR_ENA_SCA | (ch ? AR_SEL_SCA_1:AR_SEL_SCA_0))
+#define ARC_SET_OFF(iobase)	outb(iobase+AR_MSCA_EN, 0)
+
+#define ARUNIT2SC(unit)		ar_sc_ind[unit]
+
+static struct ar_hardc {
+	int cunit;
+	struct ar_softc *sc;
+	u_short iobase;
+	int startunit;
+	int numports;
+	caddr_t mem_start;
+	caddr_t mem_end;
+
+	u_int memsize;		/* in bytes */
+	u_char bustype;		/* ISA, MCA, PCI.... */
+	u_char interface;	/* X21, V.35, EIA-530.... */
+	u_char revision;
+	u_char handshake;	/* handshake lines supported by card. */
+
+	u_char txc_dtr[NPORT/NCHAN]; /* the register is write only */
+	u_int txc_dtr_off[NPORT/NCHAN];
+
+	sca_regs *sca;
+
+	struct kern_devconf kdc;
+}ar_hardc[NAR];
+
+struct ar_softc {
+	struct sppp ifsppp;
+	int unit;            /* With regards to all ar devices */
+	int subunit;         /* With regards to this card */
+	struct ar_hardc *hc;
+	caddr_t bpf;
+
+	u_int txdesc;        /* On card address */
+	u_int txstart;       /* On card address */
+	u_int txend;         /* On card address */
+	u_int txtail;        /* Index of first unused buffer */
+	u_int txmax;         /* number of usable buffers/descriptors */
+
+	u_int rxdesc;        /* On card address */
+	u_int rxstart;       /* On card address */
+	u_int rxend;         /* On card address */
+	u_int rxhind;        /* Index to the head of the rx buffers. */
+	u_int rxmax;         /* number of usable buffers/descriptors */
+
+	int scano;
+	int scachan;
+
+	struct kern_devconf kdc;
+};
+
+struct ar_softc *ar_sc_ind[NAR*NPORT];
+
+int arprobe(struct isa_device *id);
+int arattach(struct isa_device *id);
+
+/*
+ * This translate from irq numbers to
+ * the value that the arnet card needs
+ * in the lower part of the AR_INT_SEL
+ * register.
+ */
+static int irqtable[16] = {
+	0,	/*  0 */
+	0,	/*  1 */
+	0,	/*  2 */
+	1,	/*  3 */
+	0,	/*  4 */
+	2,	/*  5 */
+	0,	/*  6 */
+	3,	/*  7 */
+	0,	/*  8 */
+	0,	/*  9 */
+	4,	/* 10 */
+	5,	/* 11 */
+	6,	/* 12 */
+	0,	/* 13 */
+	0,	/* 14 */
+	7	/* 15 */
+};
+
+struct isa_driver ardriver = {arprobe, arattach, "arc"};
+
+static struct kern_devconf kdc_ar_template = { 
+	0, 0, 0, 
+	"ar", 0, { MDDT_ISA, 0, "net" },
+	isa_generic_externalize, 0, 0, ISA_EXTERNALLEN, 
+	&kdc_isa0, 
+	0,
+	DC_UNCONFIGURED, 
+	"Arnet SYNC/570i Port",
+	DC_CLS_NETIF
+};
+
+static struct kern_devconf kdc_arc_template = { 
+	0, 0, 0, 
+	"arc", 0, { MDDT_ISA, 0, "net" },
+	isa_generic_externalize, 0, 0, ISA_EXTERNALLEN, 
+	&kdc_isa0, 
+	0,
+	DC_UNCONFIGURED, 
+	"Arnet SYNC/570i Adapter",
+	DC_CLS_NETIF
+};
+
+void arstart(struct ifnet *ifp);
+int arioctl(struct ifnet *ifp, int cmd, caddr_t data);
+void arwatchdog(int port_number);
+void arinit(int port_number);
+
+static void ar_up(struct ar_softc *sc);
+static void ar_down(struct ar_softc *sc);
+static void arc_init(struct isa_device *id);
+static void ar_init_sca(struct ar_hardc *hc, int scano);
+static void ar_init_msci(struct ar_softc *sc);
+static void ar_init_rx_dmac(struct ar_softc *sc);
+static void ar_init_tx_dmac(struct ar_softc *sc);
+static void ar_dmac_intr(struct ar_hardc *hc, int scano, u_char isr);
+static void ar_msci_intr(struct ar_hardc *hc, int scano, u_char isr);
+static void ar_timer_intr(struct ar_hardc *hc, int scano, u_char isr);
+
+static inline void ar_registerdev(int ctlr, int unit)
+{
+	struct ar_softc *sc;
+	
+	sc = &ar_hardc[ctlr].sc[unit];
+	sc->kdc = kdc_ar_template;
+
+	sc->kdc.kdc_unit = ar_hardc[ctlr].startunit + unit;
+	sc->kdc.kdc_parentdata = &ar_hardc[ctlr].kdc;
+	dev_attach(&sc->kdc);
+}
+
+static inline void arc_registerdev(struct isa_device *dvp)
+{
+        int unit = dvp->id_unit;
+	struct ar_hardc *hc = &ar_hardc[dvp->id_unit];
+
+	hc->kdc = kdc_arc_template;
+
+        hc->kdc.kdc_unit = unit;
+        hc->kdc.kdc_parentdata = dvp;
+        dev_attach(&hc->kdc);
+}
+
+
+/*
+ * Register the Adapter.
+ * Probe to see if it is there.
+ * Get its information and fill it in.
+ */
+int arprobe(struct isa_device *id)
+{
+	struct ar_hardc *hc = &ar_hardc[id->id_unit];
+	u_int tmp;
+	u_short port;
+
+	/*
+	 * Register the card.
+	 */
+	arc_registerdev(id);
+
+	/*
+	 * Now see if the card is realy there.
+	 *
+	 * XXX For now I just check the undocumented ports
+	 * for "570". We will probably have to do more checking.
+	 */
+	port = id->id_iobase;
+
+	if((inb(port+AR_ID_5) != '5') || (inb(port+AR_ID_7) != '7') ||
+	   (inb(port+AR_ID_0) != '0'))
+		return 0;
+	/*
+	 * We have a card here, fill in what we can.
+	 */
+	tmp = inb(port + AR_BMI);
+	hc->bustype = tmp & AR_BUS_MSK;
+	hc->memsize = (tmp & AR_MEM_MSK) >> AR_MEM_SHFT;
+	hc->memsize = 1 << hc->memsize;
+	hc->memsize <<= 16;
+	hc->interface = (tmp & AR_IFACE_MSK);
+	hc->revision = inb(port + AR_REV);
+	hc->numports = inb(port + AR_PNUM);
+	hc->handshake = inb(port + AR_HNDSH);
+
+	id->id_msize = ARC_WIN_SIZ;
+
+	hc->iobase = id->id_iobase;
+	hc->mem_start = id->id_maddr;
+	hc->mem_end = id->id_maddr + id->id_msize;
+	hc->cunit = id->id_unit;
+
+	switch(hc->interface) {
+	case AR_IFACE_EIA_232:
+		printf("ar%d: The EIA 232 interface is not supported.\n",
+			id->id_unit);
+		return 0;
+	case AR_IFACE_V_35:
+		break;
+	case AR_IFACE_EIA_530:
+		printf("ar%d: WARNING: The EIA 530 interface is untested.\n",
+			id->id_unit);
+		break;
+	case AR_IFACE_X_21:
+		break;
+	case AR_IFACE_COMBO:
+		printf("ar%d: WARNING: The COMBO interface is untested.\n",
+			id->id_unit);
+		break;
+	}
+
+	switch(hc->numports) {
+	case 2:
+		hc->kdc.kdc_description = "Arnet SYNC/570i 2 Port Adapter";
+		break;
+	case 4:
+		hc->kdc.kdc_description = "Arnet SYNC/570i 4 Port Adapter";
+		break;
+	}
+
+	if(id->id_unit == 0)
+		hc->startunit = 0;
+	else
+		hc->startunit = ar_hardc[id->id_unit - 1].startunit +
+				ar_hardc[id->id_unit - 1].numports;
+
+	/*
+	 * Do a little sanity check.
+	 */
+	if((hc->numports > NPORT) || (hc->memsize > (512*1024)))
+		return 0;
+
+	return ARC_IO_SIZ;      /* return the amount of IO addresses used. */
+}
+
+
+/*
+ * Malloc memory for the softc structures.
+ * Reset the card to put it in a known state.
+ * Register the ports on the adapter.
+ * Fill in the info for each port.
+ * Attach each port to sppp and bpf.
+ */
+int arattach(struct isa_device *id)
+{
+	struct ar_hardc *hc = &ar_hardc[id->id_unit];
+	struct ar_softc *sc;
+	struct ifnet *ifp;
+	int unit;
+	char *iface;
+
+	switch(hc->interface) {
+	default: iface = "UNKNOWN"; break;
+	case AR_IFACE_EIA_232: iface = "EIA-232"; break;
+	case AR_IFACE_V_35: iface = "EIA-232 or V.35"; break;
+	case AR_IFACE_EIA_530: iface = "EIA-530"; break;
+	case AR_IFACE_X_21: iface = "X.21"; break;
+	case AR_IFACE_COMBO: iface = "COMBO X.21 / EIA-530"; break;
+	}
+
+	printf("arc%d: %uK RAM, %u ports, rev %u, "
+		"%s interface.\n",
+		id->id_unit,
+		hc->memsize/1024,
+		hc->numports,
+		hc->revision,
+		iface);
+	
+	hc->kdc.kdc_state = DC_BUSY;
+
+	arc_init(id);
+
+	sc = hc->sc;
+
+	for(unit=0;unit<hc->numports;unit+=NCHAN)
+		ar_init_sca(hc, unit / NCHAN);
+
+	/*
+	 * Now configure each port on the card.
+	 */
+	for(unit=0;unit<hc->numports;sc++,unit++) {
+		sc->hc = hc;
+		sc->subunit = unit;
+		sc->unit = hc->startunit + unit;
+		sc->scano = unit / NCHAN;
+		sc->scachan = unit%NCHAN;
+
+		ar_registerdev(id->id_unit, unit);
+
+		ar_init_rx_dmac(sc);
+		ar_init_tx_dmac(sc);
+		ar_init_msci(sc);
+
+		ifp = &sc->ifsppp.pp_if;
+
+		ifp->if_unit = hc->startunit + unit;
+		ifp->if_name = "ar";
+		ifp->if_mtu = PP_MTU;
+		ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
+		ifp->if_ioctl = arioctl;
+		ifp->if_start = arstart;
+		ifp->if_watchdog = arwatchdog;
+		ifp->if_init = arinit;
+
+		sc->ifsppp.pp_flags = PP_KEEPALIVE;
+
+		sc->kdc.kdc_state = DC_IDLE;
+
+		printf("ar%d: Adapter %d, port %d.\n",
+			sc->unit,
+			hc->cunit,
+			sc->subunit);
+
+		sppp_attach((struct ifnet *)&sc->ifsppp);
+		if_attach(ifp);
+
+#if NBPFILTER > 0
+		bpfattach(&sc->bpf, ifp, DLT_PPP, PPP_HEADER_LEN);
+#endif
+	}
+
+	ARC_SET_OFF(hc->iobase);
+
+	return 1;
+}
+
+/*
+ * First figure out which SCA gave the interrupt.
+ * Process it.
+ * See if there is other interrupts pending.
+ * Repeat until there is no more interrupts.
+ */
+void arintr(int unit)
+{
+	struct ar_hardc *hc = &ar_hardc[unit];
+	sca_regs *sca = hc->sca;
+	u_char isr0, isr1, isr2, arisr;
+	int scano;
+	static int intno = 0;
+
+	arisr = inb(hc->iobase + AR_ISTAT);
+
+	while(arisr & AR_BD_INT) {
+		if(arisr & AR_INT_0)
+			scano = 0;
+		else if(arisr & AR_INT_1)
+			scano = 1;
+		else {
+			/* XXX Oops this shouldn't happen. */
+			printf("arc%d: Interrupted with no interrupt.\n", unit);
+			return;
+		}
+
+		ARC_SET_SCA(hc->iobase, scano);
+
+		isr0 = sca->isr0;
+		isr1 = sca->isr1;
+		isr2 = sca->isr2;
+
+		/*
+		 * Acknoledge all the interrupts pending.
+		 */
+		sca->isr0 = isr0;
+		sca->isr1 = isr1;
+		sca->isr2 = isr2;
+
+		TRC(printf("ARINTR %d, isr0 %x, isr1 %x, isr2 %x\n", intno++, 
+			isr0,
+			isr1,
+			isr2));
+		if(isr0)
+			ar_msci_intr(hc, scano, isr0);
+
+		if(isr1)
+			ar_dmac_intr(hc, scano, isr1);
+
+		if(isr2)
+			ar_timer_intr(hc, scano, isr2);
+
+		/*
+		 * Proccess the second sca's interrupt if available.
+		 * Else see if there are any new interrupts.
+		 */
+		if((arisr & AR_INT_0) && (arisr & AR_INT_1))
+			arisr &= ~AR_INT_0;
+		else
+			arisr = inb(hc->iobase + AR_ISTAT);
+	}
+
+	ARC_SET_OFF(hc->iobase);
+}
+
+
+/*
+ * This function will be called from the upper level when a user add a
+ * packet to be send, and from the interrupt handler after a finished
+ * transmit.
+ *
+ * NOTE: it should run at spl_imp().
+ *
+ * Transmitter idle state is indicated by the IFF_OACTIVE flag. The function
+ * that clears that should ensure that the transmitter and it's DMA is
+ * in a "good" idle state.
+ */
+void arstart(struct ifnet *ifp)
+{
+	struct ar_softc *sc = ARUNIT2SC(ifp->if_unit);
+	int i, len, tlen;
+	struct mbuf *mtx;
+	u_char *txdata;
+	sca_descriptor *txdesc;
+	static int intno = 0;
+
+	if(!(ifp->if_flags & IFF_RUNNING))
+		return;
+  
+	mtx = sppp_dequeue(ifp);
+	if(!mtx)
+		return;
+
+	intno++;
+
+	/*
+	 * It is OK to set the memory window outside the loop because
+	 * all tx buffers and descriptors are assumed to be in the same
+	 * 16K window.
+	 */
+	ARC_SET_MEM(sc->hc->iobase, sc->txdesc);
+
+	/*
+	 * We stay in this loop until there is nothing in the
+	 * TX queue left or the tx buffer is full.
+	 */
+	i = 0;
+	txdesc = (sca_descriptor *)
+		(sc->hc->mem_start + (sc->txdesc & ARC_WIN_MSK));
+	txdata = (u_char *)(sc->hc->mem_start + (sc->txstart & ARC_WIN_MSK));
+	for(;;) {
+		len = mtx->m_pkthdr.len;
+
+		TRC(printf("ar%d: ARstart %d, len %u\n", sc->unit, intno, len));
+
+		/*
+		 * We can do this because the tx buffers don't wrap.
+		 */
+		m_copydata(mtx, 0, len, txdata);
+		tlen = len;
+		while(tlen > AR_BUF_SIZ) {
+			txdesc->stat = 0;
+			txdesc->len = AR_BUF_SIZ;
+			tlen -= AR_BUF_SIZ;
+			txdesc++;
+			txdata += AR_BUF_SIZ;
+			i++;
+		}
+		/* XXX Move into the loop? */
+		txdesc->stat = SCA_DESC_EOM;
+		txdesc->len = tlen;
+		txdesc++;
+		txdata += AR_BUF_SIZ;
+		i++;
+
+#if NBPFILTER > 0
+		if(sc->bpf)
+			bpf_mtap(sc->bpf, mtx);
+#endif
+		m_freem(mtx);
+		++sc->ifsppp.pp_if.if_opackets;
+
+		/*
+		 * Check if we have space for another mbuf.
+		 * XXX This is hardcoded. A packet won't be larger
+		 * than 3 buffers (3 x 512).
+		 */
+		if((i + 3) >= sc->txmax)
+			break;
+
+		mtx = sppp_dequeue(ifp);
+		if(!mtx)
+			break;
+	}
+
+	sc->txtail = i;
+
+	/*
+	 * Mark the last descriptor, so that the SCA know where
+	 * to stop.
+	 */
+	txdesc--;
+	txdesc->stat |= SCA_DESC_EOT;
+
+#if 0
+	printf("ARstart: %p desc->cp %x\n", &txdesc->cp, txdesc->cp);
+	printf("ARstart: %p desc->bp %x\n", &txdesc->bp, txdesc->bp);
+	printf("ARstart: %p desc->bpb %x\n", &txdesc->bpb, txdesc->bpb);
+	printf("ARstart: %p desc->len %x\n", &txdesc->len, txdesc->len);
+	printf("ARstart: %p desc->stat %x\n", &txdesc->stat, txdesc->stat);
+#endif
+
+	/*
+	 * Start DMA.
+	 * XXX For now we always start from the start.
+	 */
+	{
+		dmac_channel *dmac = &sc->hc->sca->dmac[DMAC_TXCH(sc->scachan)];
+
+		ARC_SET_SCA(sc->hc->iobase, sc->scano);
+		dmac->cda = (u_short)(sc->txdesc & 0xffff);
+
+		txdesc = (sca_descriptor *)sc->txdesc;
+		dmac->eda = (u_short)((u_int)&txdesc[i]);
+		dmac->dsr = SCA_DSR_DE;
+	}
+
+	ifp->if_flags |= IFF_OACTIVE;
+	ifp->if_timer = 2; /* Value in seconds. */
+	ARC_SET_OFF(sc->hc->iobase);
+}
+
+int arioctl(struct ifnet *ifp, int cmd, caddr_t data)
+{
+	int s, error;
+	int was_up, should_be_up;
+	struct sppp *sp = (struct sppp *)ifp;
+	struct ar_softc *sc = ARUNIT2SC(ifp->if_unit);
+
+	TRC(printf("ar%d: arioctl.\n", ifp->if_unit);)
+
+	if(cmd == SIOCSIFFLAGS) {
+		if(ifp->if_flags & IFF_LINK2)
+			sp->pp_flags |= PP_CISCO;
+		else
+			sp->pp_flags &= ~PP_CISCO;
+	}
+
+	was_up = ifp->if_flags & IFF_RUNNING;
+
+	error = sppp_ioctl(ifp, cmd, data);
+	TRC(printf("ar%d: ioctl: ifsppp.pp_flags = %x, if_flags %x.\n", 
+		ifp->if_unit, ((struct sppp *)ifp)->pp_flags, ifp->if_flags);)
+	if(error)
+		return error;
+
+	if((cmd != SIOCSIFFLAGS) && cmd != (SIOCSIFADDR))
+		return 0;
+
+	TRC(printf("ar%d: arioctl %s.\n", ifp->if_unit, 
+		(cmd == SIOCSIFFLAGS) ? "SIOCSIFFLAGS" : "SIOCSIFADDR");)
+
+	s = splimp();
+	should_be_up = ifp->if_flags & IFF_RUNNING;
+
+	if(!was_up && should_be_up) {
+		/* Interface should be up -- start it. */
+		ar_up(sc);
+		arstart(ifp);
+		/* XXX Maybe clear the IFF_UP flag so that the link
+		 * will only go up after sppp lcp and ipcp negotiation.
+		 */
+	} else if(was_up && !should_be_up) {
+		/* Interface should be down -- stop it. */
+		ar_down(sc);
+		sppp_flush(ifp);
+	}
+	splx(s);
+	return 0;
+}
+
+/*
+ * This is to catch lost tx interrupts.
+ */
+void arwatchdog(int unit)
+{
+	struct ar_softc *sc = ARUNIT2SC(unit);
+
+	if(!(sc->ifsppp.pp_if.if_flags & IFF_RUNNING))
+		return;
+
+	/* XXX if(sc->ifsppp.pp_if.if_flags & IFF_DEBUG) */
+		printf("ar%d: transmit failed.\n", unit);
+
+	ARC_SET_SCA(sc->hc->iobase, sc->scano);
+	sc->hc->sca->msci[sc->scachan].cmd = SCA_CMD_TXABORT;
+
+	ar_down(sc);
+	ar_up(sc);
+
+	sc->ifsppp.pp_if.if_flags &= ~IFF_OACTIVE;
+
+	arstart(&sc->ifsppp.pp_if);
+}
+
+static void ar_up(struct ar_softc *sc)
+{
+	sca_regs *sca = sc->hc->sca;
+	msci_channel *msci = &sca->msci[sc->scachan];
+
+	TRC(printf("ar%d: sca %p, msci %p, ch %d\n",
+		sc->unit, sca, msci, sc->scachan));
+	sc->kdc.kdc_state = DC_BUSY;
+
+	/*
+	 * Enable transmitter and receiver.
+	 * Raise DTR and RTS.
+	 * Enable interrupts.
+	 */
+	ARC_SET_SCA(sc->hc->iobase, sc->scano);
+
+	/* XXX
+	 * What about using AUTO mode in msci->md0 ???
+	 * And what about CTS/DCD etc... ?
+	 */
+	if(sc->hc->handshake & AR_SHSK_RTS)
+		msci->ctl |= SCA_CTL_RTS;
+	if(sc->hc->handshake & AR_SHSK_DTR) {
+		sc->hc->txc_dtr[sc->scano] |= sc->scachan ? 
+			AR_TXC_DTR_DTR1 : AR_TXC_DTR_DTR0;
+		outb(sc->hc->iobase + sc->hc->txc_dtr_off[sc->scano],
+			sc->hc->txc_dtr[sc->scano]);
+	}
+
+	if(sc->scachan == 0) {
+		sca->ier0 |= 0x0F;
+		sca->ier1 |= 0x0F;
+	} else {
+		sca->ier0 |= 0xF0;
+		sca->ier1 |= 0xF0;
+	}
+
+	msci->cmd = SCA_CMD_RXENABLE;
+	inb(sc->hc->iobase + AR_ID_5); /* XXX slow it down a bit. */
+	msci->cmd = SCA_CMD_TXENABLE;
+
+	ARC_SET_OFF(sc->hc->iobase);
+}
+
+static void ar_down(struct ar_softc *sc)
+{
+	sca_regs *sca = sc->hc->sca;
+	msci_channel *msci = &sca->msci[sc->scachan];
+
+	sc->kdc.kdc_state = DC_IDLE;
+
+	/*
+	 * Disable transmitter and receiver.
+	 * Lower DTR and RTS.
+	 * Disable interrupts.
+	 */
+	ARC_SET_SCA(sc->hc->iobase, sc->scano);
+	msci->cmd = SCA_CMD_RXDISABLE;
+	inb(sc->hc->iobase + AR_ID_5); /* XXX slow it down a bit. */
+	msci->cmd = SCA_CMD_TXDISABLE;
+
+	if(sc->hc->handshake & AR_SHSK_RTS)
+		msci->ctl &= ~SCA_CTL_RTS;
+	if(sc->hc->handshake & AR_SHSK_DTR) {
+		sc->hc->txc_dtr[sc->scano] |= sc->scachan ? 
+			AR_TXC_DTR_DTR1 : AR_TXC_DTR_DTR0;
+		outb(sc->hc->iobase + sc->hc->txc_dtr_off[sc->scano],
+			sc->hc->txc_dtr[sc->scano]);
+	}
+
+	if(sc->scachan == 0) {
+		sca->ier0 &= ~0x0F;
+		sca->ier1 &= ~0x0F;
+	} else {
+		sca->ier0 &= ~0xF0;
+		sca->ier1 &= ~0xF0;
+	}
+
+	ARC_SET_OFF(sc->hc->iobase);
+}
+
+/*
+ * I don't think anything ever calls this function.
+ */
+void arinit(int unit)
+  {
+  int s;
+  struct ar_softc *sc = ARUNIT2SC(unit);
+
+  printf("ar%d: OOPS, so somebody do call arinit!\n", unit);
+
+  s = splimp();
+  ar_down(sc);
+  ar_up(sc);
+  splx(s);
+  }
+
+/*
+ * Initialize the card, allocate memory for the ar_softc structures
+ * and fill in the pointers.
+ */
+void arc_init(struct isa_device *id)
+{
+	struct ar_hardc *hc = &ar_hardc[id->id_unit];
+	struct ar_softc *sc;
+	int x;
+	u_int chanmem;
+	u_int bufmem;
+	u_int next;
+	u_int descneeded;
+	u_char isr, mar;
+
+	sc = hc->sc = malloc(hc->numports * sizeof(struct ar_softc),
+				M_DEVBUF, M_WAITOK);
+	bzero(sc, hc->numports * sizeof(struct ar_softc));
+
+	/*
+	 * reset the card and wait at least 1uS.
+	 */
+	outb(hc->iobase + AR_TXC_DTR0, AR_TXC_DTR_RESET);
+	DELAY(2);
+	outb(hc->iobase + AR_TXC_DTR0, AR_TXC_DTR_NOTRESET);
+
+	hc->txc_dtr[0] = AR_TXC_DTR_NOTRESET;
+	hc->txc_dtr[1] = 0;
+	hc->txc_dtr_off[0] = AR_TXC_DTR0;
+	hc->txc_dtr_off[1] = AR_TXC_DTR2;
+
+	/*
+	 * Configure the card.
+	 * Mem address, irq, 
+	 */
+	mar = kvtop(id->id_maddr) >> 16;
+	isr = irqtable[ffs(id->id_irq) - 1] << 1;
+	if(isr == 0)
+		printf("ar%d: Warning illegal interrupt %d\n",
+			id->id_unit, ffs(id->id_irq) - 1);
+	isr = isr | ((kvtop(id->id_maddr) & 0xc000) >> 10);
+
+	hc->sca = (sca_regs *)hc->mem_start;
+
+	outb(hc->iobase + AR_MEM_SEL, mar);
+	outb(hc->iobase + AR_INT_SEL, isr | AR_INTS_CEN);
+
+	/*
+	 * Make TX clock output and enable TX.
+	 */
+	hc->txc_dtr[0] |= AR_TXC_DTR_TX0 | AR_TXC_DTR_TX1 |
+			  AR_TXC_DTR_TXCS0 | AR_TXC_DTR_TXCS1;
+	outb(hc->iobase + AR_TXC_DTR0, hc->txc_dtr[0]);
+	if(hc->numports > NCHAN) {
+		hc->txc_dtr[1] |= AR_TXC_DTR_TX0 | AR_TXC_DTR_TX1 |
+				  AR_TXC_DTR_TXCS0 | AR_TXC_DTR_TXCS1;
+		outb(hc->iobase + AR_TXC_DTR2, hc->txc_dtr[1]);
+	}
+
+	chanmem = hc->memsize / hc->numports;
+	next = 0;
+
+	for(x=0;x<hc->numports;x++, sc++) {
+		sc->txdesc = next;
+		bufmem = 16 * 1024;
+		descneeded = bufmem / AR_BUF_SIZ;
+		sc->txstart = sc->txdesc +
+				((((descneeded * sizeof(sca_descriptor)) /
+					AR_BUF_SIZ) + 1) * AR_BUF_SIZ);
+		sc->txend = next + bufmem;
+		sc->txmax = (sc->txend - sc->txstart) / AR_BUF_SIZ;
+		next += bufmem;
+
+		TRC(printf("ar%d: txdesc %x, txstart %x, txend %x, txmax %d\n",
+			x,
+			sc->txdesc, sc->txstart, sc->txend, sc->txmax));
+
+		sc->rxdesc = next;
+		bufmem = chanmem - bufmem;
+		descneeded = bufmem / AR_BUF_SIZ;
+		sc->rxstart = sc->rxdesc +
+				((((descneeded * sizeof(sca_descriptor)) /
+					AR_BUF_SIZ) + 1) * AR_BUF_SIZ);
+		sc->rxend = next + bufmem;
+		sc->rxmax = (sc->rxend - sc->rxstart) / AR_BUF_SIZ;
+		next += bufmem;
+
+		/*
+		 * This is by ARUNIT2SC().
+		 */
+		ar_sc_ind[x] = sc;
+	}
+}
+
+
+/*
+ * The things done here are channel independent.
+ *
+ *   Configure the sca waitstates.
+ *   Configure the global interrupt registers.
+ *   Enable master dma enable.
+ */
+static void ar_init_sca(struct ar_hardc *hc, int scano)
+{
+	sca_regs *sca = hc->sca;
+
+	ARC_SET_SCA(hc->iobase, scano);
+
+	/*
+	 * Do the wait registers.
+	 * Set everything to 0 wait states.
+	 */
+	sca->pabr0 = 0;
+	sca->pabr1 = 0;
+	sca->wcrl  = 0;
+	sca->wcrm  = 0;
+	sca->wcrh  = 0;
+
+	/*
+	 * Configure the interrupt registers.
+	 * Most are cleared until the interface is configured.
+	 */
+	sca->ier0 = 0x00; /* MSCI interrupts... Not used with dma. */
+	sca->ier1 = 0x00; /* DMAC interrupts */
+	sca->ier2 = 0x00; /* TIMER interrupts... Not used yet. */
+	sca->itcr = 0x00; /* Use ivr and no intr ack */
+	sca->ivr  = 0x40; /* Fill in the interrupt vector. */
+	sca->imvr = 0x40;
+
+	/*
+	 * Configure the timers.
+	 * XXX Later
+	 */
+
+
+	sca->dmer = SCA_DMER_EN; /* Enable all dma channels. */
+}
+
+
+/*
+ * Configure the msci
+ *
+ * NOTE: The serial port configuration is hardcoded at the moment.
+ */
+void ar_init_msci(struct ar_softc *sc)
+{
+	msci_channel *msci = &sc->hc->sca->msci[sc->scachan];
+
+	ARC_SET_SCA(sc->hc->iobase, sc->scano);
+
+	msci->cmd = SCA_CMD_RESET;
+
+	msci->md0 = SCA_MD0_CRC_1 |
+		    SCA_MD0_CRC_CCITT |
+		    SCA_MD0_CRC_ENABLE |
+		    SCA_MD0_MODE_HDLC;
+	msci->md1 = SCA_MD1_NOADDRCHK;
+	msci->md2 = SCA_MD2_DUPLEX | SCA_MD2_NRZ;
+
+	/*
+	 * Acording to the manual I should give a reset after changing the
+	 * mode registers.
+	 */
+	msci->cmd = SCA_CMD_RXRESET;
+	msci->ctl = SCA_CTL_IDLPAT | SCA_CTL_UDRNC;
+
+	/*
+	 * For now all interfaces are programmed to use the RX clock for
+	 * the TX clock.
+	 */
+	switch(sc->hc->interface) {
+	case AR_IFACE_V_35:
+	case AR_IFACE_X_21:
+	case AR_IFACE_EIA_530:
+	case AR_IFACE_COMBO:
+		msci->rxs = SCA_RXS_CLK_RXC0 | SCA_RXS_DIV1;
+		msci->txs = SCA_TXS_CLK_RX | SCA_TXS_DIV1;
+	}
+
+	msci->tmc = 153;   /* This give 64k for loopback */
+
+	/* XXX
+	 * Disable all interrupts for now. I think if you are using
+	 * the dmac you don't use these interrupts.
+	 */
+	msci->ie0 = 0;
+	msci->ie1 = 0x0C; /* XXX CTS and DCD (DSR on 570I) level change. */
+	msci->ie2 = 0;
+	msci->fie = 0;
+
+	msci->sa0 = 0;
+	msci->sa1 = 0;
+
+	msci->idl = 0x7E; /* XXX This is what cisco does. */
+
+	/*
+	 * This is what the ARNET diags use.
+	 */
+	msci->rrc  = 0x0E;
+	msci->trc0 = 0x12;
+	msci->trc1 = 0x1F;
+}
+
+/*
+ * Configure the rx dma controller.
+ */
+void ar_init_rx_dmac(struct ar_softc *sc)
+{
+	dmac_channel *dmac = &sc->hc->sca->dmac[DMAC_RXCH(sc->scachan)];
+	sca_descriptor *rxd;
+	u_int rxbuf;
+	u_int rxda;
+	u_int rxda_d;
+
+	ARC_SET_MEM(sc->hc->iobase, sc->rxdesc);
+
+	rxd = (sca_descriptor *)(sc->hc->mem_start + (sc->rxdesc&ARC_WIN_MSK));
+	rxda_d = (u_int)sc->hc->mem_start - (sc->rxdesc & ~ARC_WIN_MSK);
+
+	for(rxbuf=sc->rxstart;rxbuf<sc->rxend;rxbuf += AR_BUF_SIZ, rxd++) {
+		rxda = (u_int)&rxd[1] - rxda_d;
+		rxd->cp = (u_short)(rxda & 0xfffful);
+
+		TRC(printf("Descrp %p, data pt %p, data long %lx, ",
+			&sc->rxdesc[x], rxinuse->buf, rxbuf));
+
+		rxd->bp = (u_short)(rxbuf & 0xfffful);
+		rxd->bpb = (u_char)((rxbuf >> 16) & 0xff);
+		rxd->len = 0;
+		rxd->stat = 0xff; /* The sca write here when it is finished. */
+
+		TRC(printf("bpb %x, bp %x.\n", rxd->bpb, rxd->bp));
+	}
+	rxd--;
+	rxd->cp = (u_short)(sc->rxdesc & 0xfffful);
+
+	sc->rxhind = 0;
+
+	ARC_SET_SCA(sc->hc->iobase, sc->scano);
+
+	dmac->dsr = 0;    /* Disable DMA transfer */
+	dmac->dcr = SCA_DCR_ABRT;
+
+	/* XXX maybe also SCA_DMR_CNTE */
+	dmac->dmr = SCA_DMR_TMOD | SCA_DMR_NF;
+	dmac->bfl = AR_BUF_SIZ;
+
+	dmac->cda = (u_short)(sc->rxdesc & 0xffff);
+	dmac->sarb = (u_char)((sc->rxdesc >> 16) & 0xff);
+
+	rxd = (sca_descriptor *)sc->rxstart;
+	dmac->eda = (u_short)((u_int)&rxd[sc->rxmax - 1] & 0xffff);
+
+	dmac->dir = 0xF0;
+
+	dmac->dsr = SCA_DSR_DE;
+}
+
+/*
+ * Configure the TX DMA descriptors.
+ * Initialize the needed values and chain the descriptors.
+ */
+void ar_init_tx_dmac(struct ar_softc *sc)
+{
+	dmac_channel *dmac = &sc->hc->sca->dmac[DMAC_TXCH(sc->scachan)];
+	sca_descriptor *txd;
+	u_int txbuf;
+	u_int txda;
+	u_int txda_d;
+
+	ARC_SET_MEM(sc->hc->iobase, sc->txdesc);
+
+	txd = (sca_descriptor *)(sc->hc->mem_start + (sc->txdesc&ARC_WIN_MSK));
+	txda_d = (u_int)sc->hc->mem_start - (sc->txdesc & ~ARC_WIN_MSK);
+
+	for(txbuf=sc->txstart;txbuf<sc->txend;txbuf += AR_BUF_SIZ, txd++) {
+		txda = (u_int)&txd[1] - txda_d;
+		txd->cp = (u_short)(txda & 0xfffful);
+
+		txd->bp = (u_short)(txbuf & 0xfffful);
+		txd->bpb = (u_char)((txbuf >> 16) & 0xff);
+		TRC(printf("ar%d: txbuf %x, bpb %x, bp %x\n",
+			sc->unit, txbuf, txd->bpb, txd->bp));
+		txd->len = 0;
+		txd->stat = 0;
+	}
+	txd--;
+	txd->cp = (u_short)(sc->txdesc & 0xfffful);
+
+	sc->txtail = (u_int)txd - (u_int)sc->hc->mem_start;
+	TRC(printf("TX Descriptors start %x, end %x.\n",
+		sc->txhead,
+		sc->txtail));
+
+	ARC_SET_SCA(sc->hc->iobase, sc->scano);
+
+	dmac->dsr = 0; /* Disable DMA */
+	dmac->dcr = SCA_DCR_ABRT;
+	dmac->dmr = SCA_DMR_TMOD | SCA_DMR_NF;
+	dmac->dir = SCA_DIR_EOT | SCA_DIR_BOF | SCA_DIR_COF;
+
+	dmac->sarb = (u_char)((sc->txdesc >> 16) & 0xff);
+}
+
+
+/*
+ * Look through the descriptors to see if there is a complete packet
+ * available. Stop if we get to where the sca is busy.
+ *
+ * Return the length and status of the packet.
+ * Return nonzero if there is a packet available.
+ */
+int ar_packet_avail(struct ar_softc *sc,
+		    int *len,
+		    u_char *rxstat)
+{
+	sca_descriptor *rxdesc;
+	sca_descriptor *endp;
+
+	ARC_SET_MEM(sc->hc->iobase, sc->rxdesc);
+	rxdesc = (sca_descriptor *)
+			(sc->hc->mem_start + (sc->rxdesc & ARC_WIN_MSK));
+	endp = rxdesc;
+	rxdesc = &rxdesc[sc->rxhind];
+	endp = &endp[sc->rxmax];
+
+	*len = 0;
+
+	while(rxdesc->stat != 0xff) {
+		*len += rxdesc->len;
+
+		if(rxdesc->stat & SCA_DESC_EOM) {
+			*rxstat = rxdesc->stat;
+			TRC(printf("ar%d: PKT AVAIL len %d, %x, bufs %u.\n",
+				sc->unit, *len, *rxstat, x));
+			return 1;
+		}
+		rxdesc++;
+		if(rxdesc == endp)
+			rxdesc = (sca_descriptor *)
+				(sc->hc->mem_start + (sc->rxdesc & ARC_WIN_MSK));
+	}
+
+	*len = 0;
+	*rxstat = 0;
+	return 0;
+}
+
+
+/*
+ * Copy a packet from the on card memory into a provided mbuf.
+ * Take into account that buffers wrap and that a packet may
+ * be larger than a buffer.
+ */
+void ar_copy_rxbuf(struct mbuf *m,
+		   struct ar_softc *sc,
+		   int len)
+{
+	sca_descriptor *rxdesc;
+	u_int rxdata;
+	u_int rxmax;
+	u_int off = 0;
+	u_int tlen;
+
+	rxdata = sc->rxstart + (sc->rxhind * AR_BUF_SIZ);
+	rxmax = sc->rxstart + (sc->rxmax * AR_BUF_SIZ);
+
+	rxdesc = (sca_descriptor *)
+			(sc->hc->mem_start + (sc->rxdesc & ARC_WIN_MSK));
+	rxdesc = &rxdesc[sc->rxhind];
+
+	while(len) {
+		tlen = (len < AR_BUF_SIZ) ? len : AR_BUF_SIZ;
+		ARC_SET_MEM(sc->hc->iobase, rxdata);
+		bcopy(sc->hc->mem_start + (rxdata & ARC_WIN_MSK), 
+			mtod(m, caddr_t) + off,
+			tlen);
+
+		off += tlen;
+		len -= tlen;
+
+		ARC_SET_MEM(sc->hc->iobase, sc->rxdesc);
+		rxdesc->len = 0;
+		rxdesc->stat = 0xff;
+
+		rxdata += AR_BUF_SIZ;
+		rxdesc++;
+		if(rxdata == rxmax) {
+			rxdata = sc->rxstart;
+			rxdesc = (sca_descriptor *)
+				(sc->hc->mem_start + (sc->rxdesc & ARC_WIN_MSK));
+		}
+	}
+}
+
+/*
+ * Just eat a packet. Update pointers to point to the next packet.
+ */
+void ar_eat_packet(struct ar_softc *sc)
+{
+	sca_descriptor *rxdesc;
+	sca_descriptor *endp;
+
+	/*
+	 * Loop until desc->stat == (0xff || EOM)
+	 * Clear the status and length in the descriptor.
+	 * Increment the descriptor.
+	 */
+	ARC_SET_MEM(sc->hc->iobase, sc->rxdesc);
+	rxdesc = (sca_descriptor *)
+		(sc->hc->mem_start + (sc->rxdesc & ARC_WIN_MSK));
+	endp = rxdesc;
+	rxdesc = &rxdesc[sc->rxhind];
+	endp = &endp[sc->rxmax];
+
+	while(rxdesc->stat != 0xff) {
+		if((rxdesc->stat & ~SCA_DESC_EOM) == 0)
+			break;
+
+		rxdesc->len = 0;
+		rxdesc->stat = 0xff;
+
+		rxdesc++;
+		sc->rxhind++;
+		if(rxdesc == endp) {
+			rxdesc = (sca_descriptor *)
+			       (sc->hc->mem_start + (sc->rxdesc & ARC_WIN_MSK));
+			sc->rxhind = 0;
+		}
+	}
+}
+
+
+/*
+ * While there is packets available in the rx buffer, read them out
+ * into mbufs and ship them off.
+ */
+void ar_get_packets(struct ar_softc *sc)
+{
+	sca_descriptor *rxdesc;
+	struct mbuf *m = NULL;
+	int i;
+	int len;
+	u_char rxstat;
+
+	while(ar_packet_avail(sc, &len, &rxstat)) {
+		if((rxstat & SCA_DESC_ERRORS) == 0) {
+			MGETHDR(m, M_DONTWAIT, MT_DATA);
+			if(m != NULL) {
+				MCLGET(m, M_DONTWAIT);
+				if((m->m_flags & M_EXT) != 0) {
+					m->m_pkthdr.rcvif = &sc->ifsppp.pp_if;
+					m->m_pkthdr.len = m->m_len = len;
+					ar_copy_rxbuf(m, sc, len);
+#if NBPFILTER > 0
+					if(sc->bpf)
+						bpf_mtap(sc->bpf, m);
+#endif
+					sppp_input(&sc->ifsppp.pp_if, m);
+					sc->ifsppp.pp_if.if_ipackets++;
+				} else {
+					m_freem(m);
+					/* eat packet if get mbuf fail!! */
+					ar_eat_packet(sc);
+				}
+			} else {
+				/* eat packet if get mbuf fail!! */
+				ar_eat_packet(sc);
+			}
+		} else {
+			msci_channel *msci = &sc->hc->sca->msci[sc->scachan];
+
+			ar_eat_packet(sc);
+
+			sc->ifsppp.pp_if.if_ierrors++;
+
+			ARC_SET_SCA(sc->hc->iobase, sc->scano);
+
+			TRCL(printf("RX%d So this does happen :), stat %x, "
+					"ST2 %x, cda %x.\n",
+					sc->scachan, 
+					rxstat, 
+					msci->st2,
+					sc->hc->sca->dmac[DMAC_RXCH(sc->scachan)].cda));
+
+			/*
+			 * Reset the rx unit.
+			 *
+			 * XXX Maybe it should only be done when certain
+			 * errors occured. ie not for CRC errors?
+			 */
+			msci->cmd = SCA_CMD_RXRESET;
+			msci->cmd = SCA_CMD_RXENABLE;
+
+			TRCL(printf("RX%d After reset: ST2 %x.\n",
+					sc->scachan, msci->st2));
+		} /* else */
+
+		i = (len + AR_BUF_SIZ - 1) / AR_BUF_SIZ;
+		sc->rxhind = (sc->rxhind + i) % sc->rxmax;
+
+		/*
+		 * Update the eda to the previous descriptor.
+		 */
+		ARC_SET_SCA(sc->hc->iobase, sc->scano);
+
+		rxdesc = (sca_descriptor *)sc->rxdesc;
+		rxdesc = &rxdesc[(sc->rxhind + sc->rxmax -1 ) % sc->rxmax];
+
+		sc->hc->sca->dmac[DMAC_RXCH(sc->scachan)].eda = 
+			(u_short)((u_int)&rxdesc & 0xffff);
+
+	} /* while */
+}
+
+
+/*
+ * All DMA interrupts come here.
+ *
+ * Each channel has two interrupts.
+ * Interrupt A for errors and Interrupt B for normal stuff like end
+ * of transmit or receive dmas.
+ */
+static void ar_dmac_intr(struct ar_hardc *hc, int scano, u_char isr1)
+{
+	u_char dsr;
+	int mch;
+	struct ar_softc *sc;
+	sca_regs *sca = hc->sca;
+	dmac_channel *dmac;
+
+	mch = 0;
+	/*
+	 * Shortcut if there is no interrupts for dma channel 0 or 1
+	 */
+	if((isr1 & 0x0F) == 0) {
+		mch = 1;
+		isr1 >>= 4;
+	}
+
+	do {
+		sc = &hc->sc[mch + (NCHAN * scano)];
+		dmac = &sca->dmac[DMAC_RXCH(mch)];
+
+		/*
+		 * Receive channel
+		 */
+		if(isr1 & 0x03) {
+			ARC_SET_SCA(hc->iobase, scano);
+
+			dsr = dmac->dsr;
+			dmac->dsr = dsr;
+
+			TRC(printf("AR: RX DSR %x\n", dsr));
+
+			/* End of frame */
+			if(dsr & SCA_DSR_EOM) {
+				ar_get_packets(sc);
+			}
+
+			/* Counter overflow */
+			if(dsr & SCA_DSR_COF) {
+				printf("ar%d: RX DMA Counter overflow, "
+					"rxpkts %lu.\n",
+					sc->unit,
+					sc->ifsppp.pp_if.if_ipackets);
+				sc->ifsppp.pp_if.if_ierrors++;
+			}
+
+			/* Buffer overflow */
+			if(dsr & SCA_DSR_BOF) {
+				printf("ar%d: RX DMA Buffer overflow, "
+					"rxpkts %lu.\n",
+					sc->unit,
+					sc->ifsppp.pp_if.if_ipackets);
+				sc->ifsppp.pp_if.if_ierrors++;
+				dmac->dsr = SCA_DSR_DE;
+			}
+
+			/* End of Transfer */
+			if(dsr & SCA_DSR_EOT) {
+				/*
+				 * If this happen, it means that we are
+				 * receiving faster than what the processor
+				 * can handle.
+				 *
+				 * XXX We should enable the dma again.
+				 */
+				printf("ar%d: RX End of transfer, rxpkts %lu.\n",
+					sc->unit,
+					sc->ifsppp.pp_if.if_ipackets);
+				sc->ifsppp.pp_if.if_ierrors++;
+			}
+		}
+
+		/*
+		 * We are finished with the 2 DMA status bits for RX now do TX.
+		 */
+		isr1 >>= 2;
+
+		/*
+		 * Transmit channel
+		 */
+		if(isr1 & 0x03) {
+			dmac = &sca->dmac[DMAC_TXCH(mch)];
+
+			ARC_SET_SCA(hc->iobase, scano);
+
+			dsr = dmac->dsr;
+			dmac->dsr = dsr;
+
+			/* Counter overflow */
+			if(dsr & SCA_DSR_COF) {
+				printf("ar%d: TX DMA Counter overflow, "
+					"txpacket no %lu.\n",
+					sc->unit,
+					sc->ifsppp.pp_if.if_opackets);
+				sc->ifsppp.pp_if.if_oerrors++;
+			}
+
+			/* Buffer overflow */
+			if(dsr & SCA_DSR_BOF) {
+				printf("ar%d: TX DMA Buffer overflow, "
+					"txpacket no %lu, dsr %02x, "
+					"cda %04x, eda %04x.\n",
+					sc->unit,
+					sc->ifsppp.pp_if.if_opackets,
+					dsr,
+					dmac->cda,
+					dmac->eda);
+				sc->ifsppp.pp_if.if_oerrors++;
+			}
+
+			/* End of Transfer */
+			if(dsr & SCA_DSR_EOT) {
+				/*
+				 * This should be the most common case.
+				 *
+				 * Clear the IFF_OACTIVE flag.
+				 *
+				 * Call arstart to start a new transmit if
+				 * there is data to transmit.
+				 */
+				sc->ifsppp.pp_if.if_flags &= ~IFF_OACTIVE;
+				sc->ifsppp.pp_if.if_timer = 0;
+
+				arstart(&sc->ifsppp.pp_if);
+			}
+		}
+		isr1 >>= 2;
+
+		mch++;
+	}while((mch<NCHAN) && isr1);
+}
+
+static void ar_msci_intr(struct ar_hardc *hc, int scano, u_char isr0)
+{
+	printf("arc%d: ARINTR: MSCI\n", hc->cunit);
+}
+
+static void ar_timer_intr(struct ar_hardc *hc, int scano, u_char isr2)
+{
+	printf("arc%d: ARINTR: TIMER\n", hc->cunit);
+}
+
+/*
+ ********************************* END ************************************
+ */
+