xref: /netbsd-src/sys/arch/sun2/dev/if_ec.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: if_ec.c,v 1.18 2010/04/05 07:19:32 joerg Exp $	*/
2 
3 /*
4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matthew Fredette.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * 3Com 3C400 device driver
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: if_ec.c,v 1.18 2010/04/05 07:19:32 joerg Exp $");
38 
39 #include "opt_inet.h"
40 #include "opt_ns.h"
41 #include "rnd.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/errno.h>
46 #include <sys/ioctl.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/syslog.h>
50 #include <sys/device.h>
51 #include <sys/endian.h>
52 #if NRND > 0
53 #include <sys/rnd.h>
54 #endif
55 
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 
60 #include <net/if_ether.h>
61 #include <net/if_media.h>
62 
63 #ifdef INET
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/in_var.h>
67 #include <netinet/ip.h>
68 #include <netinet/if_inarp.h>
69 #endif
70 
71 #ifdef NS
72 #include <netns/ns.h>
73 #include <netns/ns_if.h>
74 #endif
75 
76 #include <net/bpf.h>
77 #include <net/bpfdesc.h>
78 
79 #include <machine/cpu.h>
80 #include <machine/autoconf.h>
81 #include <machine/idprom.h>
82 #include <machine/bus.h>
83 #include <machine/intr.h>
84 
85 #include <sun2/dev/if_ecreg.h>
86 
87 /*
88  * Interface softc.
89  */
90 struct ec_softc {
91 	device_t sc_dev;
92 	void *sc_ih;
93 
94 	struct ethercom sc_ethercom;	/* ethernet common */
95 	struct ifmedia sc_media;	/* our supported media */
96 
97 	bus_space_tag_t sc_iot;	/* bus space tag */
98 	bus_space_handle_t sc_ioh;	/* bus space handle */
99 
100 	u_char sc_jammed;	/* nonzero if the net is jammed */
101 	u_char sc_colliding;	/* nonzero if the net is colliding */
102 	uint32_t sc_backoff_seed;	/* seed for the backoff PRNG */
103 
104 #if NRND > 0
105 	rndsource_element_t rnd_source;
106 #endif
107 };
108 
109 /* Macros to read and write the CSR. */
110 #define	ECREG_CSR_RD bus_space_read_2(sc->sc_iot, sc->sc_ioh, ECREG_CSR)
111 #define	ECREG_CSR_WR(val) bus_space_write_2(sc->sc_iot, sc->sc_ioh, ECREG_CSR, val)
112 
113 /* After this many collisions, the packet is dropped. */
114 #define	EC_COLLISIONS_JAMMED		16
115 
116 /*
117  * Various constants used in the backoff pseudorandom
118  * number generator.
119  */
120 #define	EC_BACKOFF_PRNG_COLL_MAX	10
121 #define	EC_BACKOFF_PRNG_MUL		1103515245
122 #define	EC_BACKOFF_PRNG_ADD		12345
123 #define	EC_BACKOFF_PRNG_MASK		0x7fffffff
124 
125 /*
126  * Prototypes
127  */
128 int ec_intr(void *);
129 void ec_reset(struct ifnet *);
130 int ec_init(struct ifnet *);
131 int ec_ioctl(struct ifnet *, u_long, void *);
132 void ec_watchdog(struct ifnet *);
133 void ec_start(struct ifnet *);
134 
135 void ec_recv(struct ec_softc *, int);
136 void ec_coll(struct ec_softc *);
137 void ec_copyin(struct ec_softc *, void *, int, size_t);
138 void ec_copyout(struct ec_softc *, const void *, int, size_t);
139 
140 int ec_mediachange(struct ifnet *);
141 void ec_mediastatus(struct ifnet *, struct ifmediareq *);
142 
143 int ec_match(device_t, cfdata_t, void *);
144 void ec_attach(device_t, device_t, void *);
145 
146 CFATTACH_DECL_NEW(ec, sizeof(struct ec_softc),
147     ec_match, ec_attach, NULL, NULL);
148 
149 /*
150  * Copy board memory to kernel.
151  */
152 void
153 ec_copyin(struct ec_softc *sc, void *p, int offset, size_t size)
154 {
155 
156 	bus_space_copyin(sc->sc_iot, sc->sc_ioh, offset, p, size);
157 }
158 
159 /*
160  * Copy from kernel space to board memory.
161  */
162 void
163 ec_copyout(struct ec_softc *sc, const void *p, int offset, size_t size)
164 {
165 
166 	bus_space_copyout(sc->sc_iot, sc->sc_ioh, offset, p, size);
167 }
168 
169 int
170 ec_match(device_t parent, cfdata_t cf, void *aux)
171 {
172 	struct mbmem_attach_args *mbma = aux;
173 	bus_space_handle_t bh;
174 	bool matched;
175 
176 	/* No default Multibus address. */
177 	if (mbma->mbma_paddr == -1)
178 		return 0;
179 
180 	/* Make sure there is something there... */
181 	if (bus_space_map(mbma->mbma_bustag, mbma->mbma_paddr, ECREG_BANK_SZ,
182 	    0, &bh))
183 		return 0;
184 	matched = (bus_space_peek_2(mbma->mbma_bustag, bh, 0, NULL) == 0);
185 	bus_space_unmap(mbma->mbma_bustag, bh, ECREG_BANK_SZ);
186 	if (!matched)
187 		return 0;
188 
189 	/* Default interrupt priority. */
190 	if (mbma->mbma_pri == -1)
191 		mbma->mbma_pri = 3;
192 
193 	return 1;
194 }
195 
196 void
197 ec_attach(device_t parent, device_t self, void *aux)
198 {
199 	struct ec_softc *sc = device_private(self);
200 	struct mbmem_attach_args *mbma = aux;
201 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
202 	uint8_t myaddr[ETHER_ADDR_LEN];
203 
204 	sc->sc_dev = self;
205 
206 	aprint_normal("\n");
207 
208 	/* Map in the board control regs. */
209 	sc->sc_iot = mbma->mbma_bustag;
210 	if (bus_space_map(mbma->mbma_bustag, mbma->mbma_paddr, ECREG_BANK_SZ,
211 	    0, &sc->sc_ioh))
212 		panic("%s: can't map regs", __func__);
213 
214 	/* Reset the board. */
215 	ECREG_CSR_WR(EC_CSR_RESET);
216 	delay(160);
217 
218 	/*
219 	 * Copy out the board ROM Ethernet address,
220 	 * and use the non-vendor-ID part to seed
221 	 * our backoff pseudorandom number generator.
222 	 */
223 	bus_space_read_region_1(sc->sc_iot, sc->sc_ioh,
224 	    ECREG_AROM, myaddr, ETHER_ADDR_LEN);
225 	sc->sc_backoff_seed =
226 	    (myaddr[3] << 16) | (myaddr[4] << 8) | (myaddr[5]) | 1;
227 
228 	/* Initialize ifnet structure. */
229 	strcpy(ifp->if_xname, device_xname(self));
230 	ifp->if_softc = sc;
231 	ifp->if_start = ec_start;
232 	ifp->if_ioctl = ec_ioctl;
233 	ifp->if_init = ec_init;
234 	ifp->if_watchdog = ec_watchdog;
235 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS;
236 	IFQ_SET_READY(&ifp->if_snd);
237 
238         /* Initialize ifmedia structures. */
239 	ifmedia_init(&sc->sc_media, 0, ec_mediachange, ec_mediastatus);
240 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
241 	ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
242 
243 	/* Now we can attach the interface. */
244 	if_attach(ifp);
245 	idprom_etheraddr(myaddr);
246 	ether_ifattach(ifp, myaddr);
247 	aprint_normal_dev(self, "address %s\n", ether_sprintf(myaddr));
248 
249 	bus_intr_establish(mbma->mbma_bustag, mbma->mbma_pri, IPL_NET, 0,
250 	    ec_intr, sc);
251 
252 #if NRND > 0
253 	rnd_attach_source(&sc->rnd_source, device_xname(self),
254 	    RND_TYPE_NET, 0);
255 #endif
256 }
257 
258 /*
259  * Reset interface.
260  */
261 void
262 ec_reset(struct ifnet *ifp)
263 {
264         int s;
265 
266         s = splnet();
267         ec_init(ifp);
268         splx(s);
269 }
270 
271 
272 /*
273  * Initialize interface.
274  */
275 int
276 ec_init(struct ifnet *ifp)
277 {
278 	struct ec_softc *sc = ifp->if_softc;
279 
280 	/* Reset the board. */
281 	ECREG_CSR_WR(EC_CSR_RESET);
282 	delay(160);
283 
284 	/* Set the Ethernet address. */
285 	bus_space_write_region_1(sc->sc_iot, sc->sc_ioh,
286 	    ECREG_ARAM, CLLADDR(sc->sc_ethercom.ec_if.if_sadl), ETHER_ADDR_LEN);
287 	ECREG_CSR_WR((ECREG_CSR_RD & EC_CSR_INTPA) | EC_CSR_AMSW);
288 	ECREG_CSR_WR(ECREG_CSR_RD & 0);
289 
290 	/* Enable interrupts. */
291 	ECREG_CSR_WR((ECREG_CSR_RD & EC_CSR_INTPA) |
292 	    EC_CSR_BBSW | EC_CSR_ABSW | EC_CSR_BINT | EC_CSR_AINT |
293 	    (ifp->if_flags & IFF_PROMISC ? EC_CSR_PROMISC : EC_CSR_PA));
294 
295 	/* Set flags appropriately. */
296 	ifp->if_flags |= IFF_RUNNING;
297 	ifp->if_flags &= ~IFF_OACTIVE;
298 
299 	/* Start output. */
300 	ec_start(ifp);
301 
302 	return 0;
303 }
304 
305 /*
306  * Start output on interface.
307  */
308 void
309 ec_start(struct ifnet *ifp)
310 {
311 	struct ec_softc *sc = ifp->if_softc;
312 	struct mbuf *m, *m0;
313 	int s;
314 	u_int count, realcount;
315 	bus_size_t off;
316 	static uint8_t padding[ETHER_MIN_LEN - ETHER_CRC_LEN] = {0};
317 
318 	s = splnet();
319 
320 	/* Don't do anything if output is active. */
321 	if ((ifp->if_flags & IFF_OACTIVE) != 0) {
322 		splx(s);
323 		return;
324 	}
325 	/* Don't do anything if the output queue is empty. */
326 	IFQ_DEQUEUE(&ifp->if_snd, m0);
327 	if (m0 == NULL) {
328 		splx(s);
329 		return;
330 	}
331 
332 	/* The BPF tap. */
333 	bpf_mtap(ifp, m0);
334 
335 	/* Size the packet. */
336 	count = EC_BUF_SZ - m0->m_pkthdr.len;
337 
338 	/* Copy the packet into the xmit buffer. */
339 	realcount = MIN(count, EC_PKT_MAXTDOFF);
340 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, ECREG_TBUF, realcount);
341 	for (off = realcount, m = m0; m != 0; off += m->m_len, m = m->m_next)
342 		ec_copyout(sc, mtod(m, uint8_t *), ECREG_TBUF + off, m->m_len);
343 	m_freem(m0);
344 	if (count - realcount)
345 		ec_copyout(sc, padding, ECREG_TBUF + off, count - realcount);
346 
347 	/* Enable the transmitter. */
348 	ECREG_CSR_WR((ECREG_CSR_RD & EC_CSR_PA) |
349 	    EC_CSR_TBSW | EC_CSR_TINT | EC_CSR_JINT);
350 	ifp->if_flags |= IFF_OACTIVE;
351 
352 	/* Done. */
353 	splx(s);
354 }
355 
356 /*
357  * Controller interrupt.
358  */
359 int
360 ec_intr(void *arg)
361 {
362 	struct ec_softc *sc = arg;
363 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
364 	int recv_first;
365 	int recv_second;
366 	int retval;
367 	struct mbuf *m0;
368 
369 	retval = 0;
370 
371 	/* Check for received packet(s). */
372 	recv_first = recv_second = 0;
373 	switch (ECREG_CSR_RD & (EC_CSR_BBSW | EC_CSR_ABSW | EC_CSR_RBBA)) {
374 
375 	case (EC_CSR_BBSW | EC_CSR_ABSW):
376 	case (EC_CSR_BBSW | EC_CSR_ABSW | EC_CSR_RBBA):
377 		/* Neither buffer is full.  Is this a transmit interrupt?
378 		 * Acknowledge the interrupt ourselves. */
379 		ECREG_CSR_WR(ECREG_CSR_RD &
380 		    (EC_CSR_TINT | EC_CSR_JINT | EC_CSR_PAMASK));
381 		ECREG_CSR_WR((ECREG_CSR_RD & EC_CSR_INTPA) |
382 		    EC_CSR_BINT | EC_CSR_AINT);
383 		break;
384 
385 	case EC_CSR_BBSW:
386 	case (EC_CSR_BBSW | EC_CSR_RBBA):
387 		/* Only the A buffer is full. */
388 		recv_first = EC_CSR_AINT;
389 		break;
390 
391 	case EC_CSR_ABSW:
392 	case (EC_CSR_ABSW | EC_CSR_RBBA):
393 		/* Only the B buffer is full. */
394 		recv_first = EC_CSR_BINT;
395 		break;
396 
397 	case 0:
398 		/* Both the A buffer and the B buffer are full, and the A
399 		 * buffer is older than the B buffer. */
400 		recv_first = EC_CSR_AINT;
401 		recv_second = EC_CSR_BINT;
402 		break;
403 
404 	case EC_CSR_RBBA:
405 		/* Both the A buffer and the B buffer are full, and the B
406 		 * buffer is older than the A buffer. */
407 		recv_first = EC_CSR_BINT;
408 		recv_second = EC_CSR_AINT;
409 		break;
410 	}
411 
412 	/* Receive packets. */
413 	if (recv_first) {
414 
415 		/* Acknowledge the interrupt. */
416 		ECREG_CSR_WR(ECREG_CSR_RD &
417 		    ((EC_CSR_BINT | EC_CSR_AINT | EC_CSR_TINT | EC_CSR_JINT |
418 		      EC_CSR_PAMASK) ^ (recv_first | recv_second)));
419 
420 		/* Receive a packet. */
421 		ec_recv(sc, recv_first);
422 
423 		/* Receive a packet. */
424 		if (recv_second)
425 			ec_recv(sc, recv_second);
426 
427 		retval++;
428 	}
429 	/* Check for a transmitted packet. */
430 	if (ifp->if_flags & IFF_OACTIVE) {
431 
432 		/* If we got a collision. */
433 		if (ECREG_CSR_RD & EC_CSR_JAM) {
434 			ECREG_CSR_WR(ECREG_CSR_RD &
435 			    (EC_CSR_BINT | EC_CSR_AINT | EC_CSR_PAMASK));
436 			sc->sc_ethercom.ec_if.if_collisions++;
437 			retval++;
438 			ec_coll(sc);
439 
440 		}
441 		/* If we transmitted a packet. */
442 		else if ((ECREG_CSR_RD & EC_CSR_TBSW) == 0) {
443 			ECREG_CSR_WR(ECREG_CSR_RD &
444 			    (EC_CSR_BINT | EC_CSR_AINT | EC_CSR_PAMASK));
445 			retval++;
446 			sc->sc_ethercom.ec_if.if_opackets++;
447 			sc->sc_jammed = 0;
448 			ifp->if_flags &= ~IFF_OACTIVE;
449 			IFQ_POLL(&ifp->if_snd, m0);
450 			if (m0 != NULL)
451 				ec_start(ifp);
452 		}
453 	} else {
454 
455 		/* Make sure we disable transmitter interrupts. */
456 		ECREG_CSR_WR(ECREG_CSR_RD &
457 		    (EC_CSR_BINT | EC_CSR_AINT | EC_CSR_PAMASK));
458 	}
459 
460 	return retval;
461 }
462 
463 /*
464  * Read in a packet from the board.
465  */
466 void
467 ec_recv(struct ec_softc *sc, int intbit)
468 {
469 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
470 	struct mbuf *m0, *m, *newm;
471 	bus_size_t buf;
472 	uint16_t status;
473 	uint16_t doff;
474 	int length, total_length;
475 
476 	buf = EC_CSR_INT_BUF(intbit);
477 
478 	/* Read in the packet status. */
479 	status = bus_space_read_2(sc->sc_iot, sc->sc_ioh, buf);
480 	doff = status & EC_PKT_DOFF;
481 
482 	for (total_length = -1, m0 = NULL;;) {
483 
484 		/* Check for an error. */
485 		if (status & (EC_PKT_FCSERR | EC_PKT_RGERR | EC_PKT_FRERR) ||
486 		    doff < EC_PKT_MINRDOFF ||
487 		    doff > EC_PKT_MAXRDOFF) {
488 			printf("%s: garbled packet, status 0x%04x; dropping\n",
489 			    device_xname(sc->sc_dev), (unsigned int)status);
490 			break;
491 		}
492 
493 		/* Adjust for the header. */
494 		total_length = doff - EC_PKT_RDOFF;
495 		buf += EC_PKT_RDOFF;
496 
497 		/* XXX - sometimes the card reports a large data offset. */
498 		if (total_length > (ETHER_MAX_LEN - ETHER_CRC_LEN)) {
499 #ifdef DEBUG
500 			printf("%s: fixing too-large length of %d\n",
501 			    device_xname(sc->sc_dev), total_length);
502 #endif
503 			total_length = (ETHER_MAX_LEN - ETHER_CRC_LEN);
504 		}
505 
506 		MGETHDR(m0, M_DONTWAIT, MT_DATA);
507 		if (m0 == NULL)
508 			break;
509 		m0->m_pkthdr.rcvif = ifp;
510 		m0->m_pkthdr.len = total_length;
511 		length = MHLEN;
512 		m = m0;
513 
514 		while (total_length > 0) {
515 			if (total_length >= MINCLSIZE) {
516 				MCLGET(m, M_DONTWAIT);
517 				if ((m->m_flags & M_EXT) == 0)
518 					break;
519 				length = MCLBYTES;
520 			}
521 			m->m_len = length = min(total_length, length);
522 			ec_copyin(sc, mtod(m, uint8_t *), buf, length);
523 			total_length -= length;
524 			buf += length;
525 
526 			if (total_length > 0) {
527 				MGET(newm, M_DONTWAIT, MT_DATA);
528 				if (newm == NULL)
529 					break;
530 				length = MLEN;
531 				m = m->m_next = newm;
532 			}
533 		}
534 		break;
535 	}
536 
537 	if (total_length == 0) {
538 		ifp->if_ipackets++;
539 
540 		/*
541 	 	* Check if there's a BPF listener on this interface.
542 	 	* If so, hand off the raw packet to BPF.
543 	 	*/
544 		bpf_mtap(ifp, m0);
545 
546 		/* Pass the packet up. */
547 		(*ifp->if_input)(ifp, m0);
548 
549 	} else {
550 		/* Something went wrong. */
551 		if (m0 != NULL)
552 			m_freem(m0);
553 		ifp->if_ierrors++;
554 	}
555 
556 	/* Give the receive buffer back to the card. */
557 	buf = EC_CSR_INT_BUF(intbit);
558 	bus_space_write_2(sc->sc_iot, sc->sc_ioh, buf, 0);
559 	ECREG_CSR_WR((ECREG_CSR_RD & EC_CSR_INTPA) |
560 	    EC_CSR_INT_BSW(intbit) | intbit);
561 }
562 
563 int
564 ec_mediachange(struct ifnet *ifp)
565 {
566 
567 	return 0;
568 }
569 
570 void
571 ec_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
572 {
573 
574 	if ((ifp->if_flags & IFF_UP) == 0)
575 		return;
576 
577 	ifmr->ifm_status = IFM_AVALID | IFM_ACTIVE;
578 }
579 
580 /*
581  * Process an ioctl request. This code needs some work - it looks pretty ugly.
582  */
583 int
584 ec_ioctl(struct ifnet *ifp, u_long cmd, void *data)
585 {
586 	struct ifaddr *ifa = (struct ifaddr *)data;
587 	struct ifreq *ifr = (struct ifreq *)data;
588 	struct ec_softc *sc = ifp->if_softc;
589 	int s, error = 0;
590 
591 	s = splnet();
592 
593 	switch (cmd) {
594 
595 	case SIOCINITIFADDR:
596 		ifp->if_flags |= IFF_UP;
597 
598 		switch (ifa->ifa_addr->sa_family) {
599 #ifdef INET
600 		case AF_INET:
601 			ec_init(ifp);
602 			arp_ifinit(ifp, ifa);
603 			break;
604 #endif
605 		default:
606 			ec_init(ifp);
607 			break;
608 		}
609 		break;
610 
611 	case SIOCSIFFLAGS:
612 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
613 			break;
614 		switch (ifp->if_flags & (IFF_UP|IFF_RUNNING)) {
615 		case IFF_RUNNING:
616 			/*
617 			 * If interface is marked down and it is running, then
618 			 * stop it.
619 			 */
620 			ifp->if_flags &= ~IFF_RUNNING;
621 			break;
622 		case IFF_UP:
623 			/*
624 			 * If interface is marked up and it is stopped, then
625 			 * start it.
626 			 */
627 			ec_init(ifp);
628 			break;
629 		default:
630 			/*
631 			 * Some other important flag might have changed, so
632 			 * reset.
633 			 */
634 			ec_reset(ifp);
635 			break;
636 		}
637 		break;
638 
639 	case SIOCGIFMEDIA:
640 	case SIOCSIFMEDIA:
641 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
642 		break;
643 
644 	default:
645 		error = ether_ioctl(ifp, cmd, data);
646 		break;
647 	}
648 
649 	splx(s);
650 	return error;
651 }
652 
653 /*
654  * Collision routine.
655  */
656 void
657 ec_coll(struct ec_softc *sc)
658 {
659 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
660 	u_short jams;
661 	struct mbuf *m0;
662 
663 	if ((++sc->sc_colliding) >= EC_COLLISIONS_JAMMED) {
664 		sc->sc_ethercom.ec_if.if_oerrors++;
665 		if (!sc->sc_jammed)
666 			printf("%s: ethernet jammed\n",
667 			    device_xname(sc->sc_dev));
668 		sc->sc_jammed = 1;
669 		sc->sc_colliding = 0;
670 		ifp->if_flags &= ~IFF_OACTIVE;
671 		IFQ_POLL(&ifp->if_snd, m0);
672 		if (m0 != NULL)
673 			ec_start(ifp);
674 	} else {
675 		jams = MAX(sc->sc_colliding, EC_BACKOFF_PRNG_COLL_MAX);
676 		sc->sc_backoff_seed =
677 		    ((sc->sc_backoff_seed * EC_BACKOFF_PRNG_MUL) +
678 		    EC_BACKOFF_PRNG_ADD) & EC_BACKOFF_PRNG_MASK;
679 		bus_space_write_2(sc->sc_iot, sc->sc_ioh, ECREG_BACKOFF,
680 		    -(((sc->sc_backoff_seed >> 8) & ~(-1 << jams)) + 1));
681 		ECREG_CSR_WR((ECREG_CSR_RD & EC_CSR_INTPA) |
682 		    EC_CSR_JAM | EC_CSR_TINT | EC_CSR_JINT);
683 	}
684 }
685 
686 /*
687  * Device timeout routine.
688  */
689 void
690 ec_watchdog(struct ifnet *ifp)
691 {
692 	struct ec_softc *sc = ifp->if_softc;
693 
694 	log(LOG_ERR, "%s: device timeout\n", device_xname(sc->sc_dev));
695 	sc->sc_ethercom.ec_if.if_oerrors++;
696 
697 	ec_reset(ifp);
698 }
699