/* $NetBSD: smc90cx6.c,v 1.38 2001/07/07 15:57:53 thorpej Exp $ */ #include __FBSDID("$FreeBSD: stable/11/sys/dev/cm/smc90cx6.c 315221 2017-03-14 02:06:03Z pfg $"); /*- * Copyright (c) 1994, 1995, 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Ignatios Souvatzis. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 THE FOUNDATION OR CONTRIBUTORS * 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. */ /* * Chip core driver for the SMC90c26 / SMC90c56 (and SMC90c66 in '56 * compatibility mode) boards */ /* #define CMSOFTCOPY */ #define CMRETRANSMIT /**/ /* #define CM_DEBUG */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE_DEPEND(if_cm, arcnet, 1, 1, 1); /* these should be elsewhere */ #define ARC_MIN_LEN 1 #define ARC_MIN_FORBID_LEN 254 #define ARC_MAX_FORBID_LEN 256 #define ARC_MAX_LEN 508 #define ARC_ADDR_LEN 1 /* for watchdog timer. This should be more than enough. */ #define ARCTIMEOUT (5*IFNET_SLOWHZ) devclass_t cm_devclass; /* * This currently uses 2 bufs for tx, 2 for rx * * New rx protocol: * * rx has a fillcount variable. If fillcount > (NRXBUF-1), * rx can be switched off from rx hard int. * Else rx is restarted on the other receiver. * rx soft int counts down. if it is == (NRXBUF-1), it restarts * the receiver. * To ensure packet ordering (we need that for 1201 later), we have a counter * which is incremented modulo 256 on each receive and a per buffer * variable, which is set to the counter on filling. The soft int can * compare both values to determine the older packet. * * Transmit direction: * * cm_start checks tx_fillcount * case 2: return * * else fill tx_act ^ 1 && inc tx_fillcount * * check tx_fillcount again. * case 2: set IFF_DRV_OACTIVE to stop arc_output from filling us. * case 1: start tx * * tint clears IFF_OACTIVE, decrements and checks tx_fillcount * case 1: start tx on tx_act ^ 1, softcall cm_start * case 0: softcall cm_start * * #define fill(i) get mbuf && copy mbuf to chip(i) */ void cm_init(void *); static void cm_init_locked(struct cm_softc *); static void cm_reset_locked(struct cm_softc *); void cm_start(struct ifnet *); void cm_start_locked(struct ifnet *); int cm_ioctl(struct ifnet *, unsigned long, caddr_t); void cm_watchdog(void *); void cm_srint_locked(void *vsc); static void cm_tint_locked(struct cm_softc *, int); void cm_reconwatch_locked(void *); /* * Release all resources */ void cm_release_resources(dev) device_t dev; { struct cm_softc *sc = device_get_softc(dev); if (sc->port_res != NULL) { bus_release_resource(dev, SYS_RES_IOPORT, 0, sc->port_res); sc->port_res = NULL; } if (sc->mem_res != NULL) { bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res); sc->mem_res = NULL; } if (sc->irq_res != NULL) { bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res); sc->irq_res = NULL; } } int cm_attach(dev) device_t dev; { struct cm_softc *sc = device_get_softc(dev); struct ifnet *ifp; u_int8_t linkaddress; ifp = sc->sc_ifp = if_alloc(IFT_ARCNET); if (ifp == NULL) return (ENOSPC); /* * read the arcnet address from the board */ GETREG(CMRESET); do { DELAY(200); } while (!(GETREG(CMSTAT) & CM_POR)); linkaddress = GETMEM(CMMACOFF); /* clear the int mask... */ sc->sc_intmask = 0; PUTREG(CMSTAT, 0); PUTREG(CMCMD, CM_CONF(CONF_LONG)); PUTREG(CMCMD, CM_CLR(CLR_POR|CLR_RECONFIG)); sc->sc_recontime = sc->sc_reconcount = 0; /* * set interface to stopped condition (reset) */ cm_stop_locked(sc); ifp->if_softc = sc; if_initname(ifp, device_get_name(dev), device_get_unit(dev)); ifp->if_output = arc_output; ifp->if_start = cm_start; ifp->if_ioctl = cm_ioctl; ifp->if_init = cm_init; /* XXX IFQ_SET_READY(&ifp->if_snd); */ ifp->if_snd.ifq_maxlen = ifqmaxlen; ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX; arc_ifattach(ifp, linkaddress); #ifdef CMSOFTCOPY sc->sc_rxcookie = softintr_establish(IPL_SOFTNET, cm_srint, sc); sc->sc_txcookie = softintr_establish(IPL_SOFTNET, (void (*)(void *))cm_start, ifp); #endif callout_init_mtx(&sc->sc_recon_ch, &sc->sc_mtx, 0); callout_init_mtx(&sc->sc_watchdog_timer, &sc->sc_mtx, 0); if_printf(ifp, "link addr 0x%02x (%d)\n", linkaddress, linkaddress); return 0; } /* * Initialize device * */ void cm_init(xsc) void *xsc; { struct cm_softc *sc = (struct cm_softc *)xsc; CM_LOCK(sc); cm_init_locked(sc); CM_UNLOCK(sc); } static void cm_init_locked(struct cm_softc *sc) { struct ifnet *ifp = sc->sc_ifp; if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { ifp->if_drv_flags |= IFF_DRV_RUNNING; cm_reset_locked(sc); } } /* * Reset the interface... * * Assumes that it is called with sc_mtx held */ void cm_reset_locked(sc) struct cm_softc *sc; { struct ifnet *ifp; int linkaddress; ifp = sc->sc_ifp; #ifdef CM_DEBUG if_printf(ifp, "reset\n"); #endif /* stop and restart hardware */ GETREG(CMRESET); do { DELAY(200); } while (!(GETREG(CMSTAT) & CM_POR)); linkaddress = GETMEM(CMMACOFF); #if defined(CM_DEBUG) && (CM_DEBUG > 2) if_printf(ifp, "reset: card reset, link addr = 0x%02x (%d)\n", linkaddress, linkaddress); #endif /* tell the routing level about the (possibly changed) link address */ arc_storelladdr(ifp, linkaddress); arc_frag_init(ifp); /* POR is NMI, but we need it below: */ sc->sc_intmask = CM_RECON|CM_POR; PUTREG(CMSTAT, sc->sc_intmask); PUTREG(CMCMD, CM_CONF(CONF_LONG)); #ifdef CM_DEBUG if_printf(ifp, "reset: chip configured, status=0x%02x\n", GETREG(CMSTAT)); #endif PUTREG(CMCMD, CM_CLR(CLR_POR|CLR_RECONFIG)); #ifdef CM_DEBUG if_printf(ifp, "reset: bits cleared, status=0x%02x\n", GETREG(CMSTAT)); #endif sc->sc_reconcount_excessive = ARC_EXCESSIVE_RECONS; /* start receiver */ sc->sc_intmask |= CM_RI; sc->sc_rx_fillcount = 0; sc->sc_rx_act = 2; PUTREG(CMCMD, CM_RXBC(2)); PUTREG(CMSTAT, sc->sc_intmask); #ifdef CM_DEBUG if_printf(ifp, "reset: started receiver, status=0x%02x\n", GETREG(CMSTAT)); #endif /* and init transmitter status */ sc->sc_tx_act = 0; sc->sc_tx_fillcount = 0; ifp->if_drv_flags |= IFF_DRV_RUNNING; ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; callout_reset(&sc->sc_watchdog_timer, hz, cm_watchdog, sc); cm_start_locked(ifp); } /* * Take interface offline */ void cm_stop_locked(sc) struct cm_softc *sc; { /* Stop the interrupts */ PUTREG(CMSTAT, 0); /* Stop the interface */ GETREG(CMRESET); /* Stop watchdog timer */ callout_stop(&sc->sc_watchdog_timer); sc->sc_timer = 0; } void cm_start(struct ifnet *ifp) { struct cm_softc *sc = ifp->if_softc; CM_LOCK(sc); cm_start_locked(ifp); CM_UNLOCK(sc); } /* * Start output on interface. Get another datagram to send * off the interface queue, and copy it to the * interface becore starting the output * * Assumes that sc_mtx is held */ void cm_start_locked(ifp) struct ifnet *ifp; { struct cm_softc *sc = ifp->if_softc; struct mbuf *m, *mp; int cm_ram_ptr; int len, tlen, offset, buffer; #ifdef CMTIMINGS u_long copystart, lencopy, perbyte; #endif #if defined(CM_DEBUG) && (CM_DEBUG > 3) if_printf(ifp, "start(%p)\n", ifp); #endif if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) return; if (sc->sc_tx_fillcount >= 2) return; m = arc_frag_next(ifp); buffer = sc->sc_tx_act ^ 1; if (m == NULL) return; #ifdef CM_DEBUG if (m->m_len < ARC_HDRLEN) m = m_pullup(m, ARC_HDRLEN);/* gcc does structure padding */ if_printf(ifp, "start: filling %d from %d to %d type %d\n", buffer, mtod(m, u_char *)[0], mtod(m, u_char *)[1], mtod(m, u_char *)[2]); #else if (m->m_len < 2) m = m_pullup(m, 2); #endif cm_ram_ptr = buffer * 512; if (m == NULL) return; /* write the addresses to RAM and throw them away */ /* * Hardware does this: Yet Another Microsecond Saved. * (btw, timing code says usually 2 microseconds) * PUTMEM(cm_ram_ptr + 0, mtod(m, u_char *)[0]); */ PUTMEM(cm_ram_ptr + 1, mtod(m, u_char *)[1]); m_adj(m, 2); /* get total length left at this point */ tlen = m->m_pkthdr.len; if (tlen < ARC_MIN_FORBID_LEN) { offset = 256 - tlen; PUTMEM(cm_ram_ptr + 2, offset); } else { PUTMEM(cm_ram_ptr + 2, 0); if (tlen <= ARC_MAX_FORBID_LEN) offset = 255; /* !!! */ else { if (tlen > ARC_MAX_LEN) tlen = ARC_MAX_LEN; offset = 512 - tlen; } PUTMEM(cm_ram_ptr + 3, offset); } cm_ram_ptr += offset; /* lets loop through the mbuf chain */ for (mp = m; mp; mp = mp->m_next) { if ((len = mp->m_len)) { /* YAMS */ bus_space_write_region_1( rman_get_bustag(sc->mem_res), rman_get_bushandle(sc->mem_res), cm_ram_ptr, mtod(mp, caddr_t), len); cm_ram_ptr += len; } } sc->sc_broadcast[buffer] = (m->m_flags & M_BCAST) != 0; sc->sc_retransmits[buffer] = (m->m_flags & M_BCAST) ? 1 : 5; if (++sc->sc_tx_fillcount > 1) { /* * We are filled up to the rim. No more bufs for the moment, * please. */ ifp->if_drv_flags |= IFF_DRV_OACTIVE; } else { #ifdef CM_DEBUG if_printf(ifp, "start: starting transmitter on buffer %d\n", buffer); #endif /* Transmitter was off, start it */ sc->sc_tx_act = buffer; /* * We still can accept another buf, so don't: * ifp->if_drv_flags |= IFF_DRV_OACTIVE; */ sc->sc_intmask |= CM_TA; PUTREG(CMCMD, CM_TX(buffer)); PUTREG(CMSTAT, sc->sc_intmask); sc->sc_timer = ARCTIMEOUT; } m_freem(m); /* * After 10 times reading the docs, I realized * that in the case the receiver NAKs the buffer request, * the hardware retries till shutdown. * This is integrated now in the code above. */ } #ifdef CMSOFTCOPY void cm_srint(void *vsc) { struct cm_softc *sc = (struct cm_softc *)vsc; CM_LOCK(sc); cm_srint_locked(vsc); CM_UNLOCK(sc); } #endif /* * Arcnet interface receiver soft interrupt: * get the stuff out of any filled buffer we find. */ void cm_srint_locked(vsc) void *vsc; { struct cm_softc *sc = (struct cm_softc *)vsc; int buffer, len, offset, type; int cm_ram_ptr; struct mbuf *m; struct arc_header *ah; struct ifnet *ifp; ifp = sc->sc_ifp; buffer = sc->sc_rx_act ^ 1; /* Allocate header mbuf */ MGETHDR(m, M_NOWAIT, MT_DATA); if (m == NULL) { /* * in case s.th. goes wrong with mem, drop it * to make sure the receiver can be started again * count it as input error (we dont have any other * detectable) */ if_inc_counter(ifp, IFCOUNTER_IERRORS, 1); goto cleanup; } m->m_pkthdr.rcvif = ifp; /* * Align so that IP packet will be longword aligned. Here we * assume that m_data of new packet is longword aligned. * When implementing PHDS, we might have to change it to 2, * (2*sizeof(ulong) - CM_HDRNEWLEN)), packet type dependent. */ cm_ram_ptr = buffer * 512; offset = GETMEM(cm_ram_ptr + 2); if (offset) len = 256 - offset; else { offset = GETMEM(cm_ram_ptr + 3); len = 512 - offset; } /* * first +2 bytes for align fixup below * second +2 bytes are for src/dst addresses */ if ((len + 2 + 2) > MHLEN) { /* attach an mbuf cluster */ if (!(MCLGET(m, M_NOWAIT))) { if_inc_counter(ifp, IFCOUNTER_IERRORS, 1); goto cleanup; } } if (m == NULL) { if_inc_counter(ifp, IFCOUNTER_IERRORS, 1); goto cleanup; } type = GETMEM(cm_ram_ptr + offset); m->m_data += 1 + arc_isphds(type); /* mbuf filled with ARCnet addresses */ m->m_pkthdr.len = m->m_len = len + 2; ah = mtod(m, struct arc_header *); ah->arc_shost = GETMEM(cm_ram_ptr + 0); ah->arc_dhost = GETMEM(cm_ram_ptr + 1); bus_space_read_region_1( rman_get_bustag(sc->mem_res), rman_get_bushandle(sc->mem_res), cm_ram_ptr + offset, mtod(m, u_char *) + 2, len); CM_UNLOCK(sc); arc_input(ifp, m); CM_LOCK(sc); m = NULL; if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); cleanup: if (m != NULL) m_freem(m); /* mark buffer as invalid by source id 0 */ PUTMEM(buffer << 9, 0); if (--sc->sc_rx_fillcount == 2 - 1) { /* was off, restart it on buffer just emptied */ sc->sc_rx_act = buffer; sc->sc_intmask |= CM_RI; /* this also clears the RI flag interrupt: */ PUTREG(CMCMD, CM_RXBC(buffer)); PUTREG(CMSTAT, sc->sc_intmask); #ifdef CM_DEBUG if_printf(ifp, "srint: restarted rx on buf %d\n", buffer); #endif } } static inline void cm_tint_locked(sc, isr) struct cm_softc *sc; int isr; { struct ifnet *ifp; int buffer; #ifdef CMTIMINGS int clknow; #endif ifp = sc->sc_ifp; buffer = sc->sc_tx_act; /* * retransmit code: * Normal situtations first for fast path: * If acknowledgement received ok or broadcast, we're ok. * else if */ if (isr & CM_TMA || sc->sc_broadcast[buffer]) if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); #ifdef CMRETRANSMIT else if (ifp->if_flags & IFF_LINK2 && sc->sc_timer > 0 && --sc->sc_retransmits[buffer] > 0) { /* retransmit same buffer */ PUTREG(CMCMD, CM_TX(buffer)); return; } #endif else if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); /* We know we can accept another buffer at this point. */ ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; if (--sc->sc_tx_fillcount > 0) { /* * start tx on other buffer. * This also clears the int flag */ buffer ^= 1; sc->sc_tx_act = buffer; /* * already given: * sc->sc_intmask |= CM_TA; * PUTREG(CMSTAT, sc->sc_intmask); */ PUTREG(CMCMD, CM_TX(buffer)); /* init watchdog timer */ sc->sc_timer = ARCTIMEOUT; #if defined(CM_DEBUG) && (CM_DEBUG > 1) if_printf(ifp, "tint: starting tx on buffer %d, status 0x%02x\n", buffer, GETREG(CMSTAT)); #endif } else { /* have to disable TX interrupt */ sc->sc_intmask &= ~CM_TA; PUTREG(CMSTAT, sc->sc_intmask); /* ... and watchdog timer */ sc->sc_timer = 0; #ifdef CM_DEBUG if_printf(ifp, "tint: no more buffers to send, status 0x%02x\n", GETREG(CMSTAT)); #endif } /* XXXX TODO */ #ifdef CMSOFTCOPY /* schedule soft int to fill a new buffer for us */ softintr_schedule(sc->sc_txcookie); #else /* call it directly */ cm_start_locked(ifp); #endif } /* * Our interrupt routine */ void cmintr(arg) void *arg; { struct cm_softc *sc = arg; struct ifnet *ifp = sc->sc_ifp; u_char isr, maskedisr; int buffer; u_long newsec; CM_LOCK(sc); isr = GETREG(CMSTAT); maskedisr = isr & sc->sc_intmask; if (!maskedisr || (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { CM_UNLOCK(sc); return; } do { #if defined(CM_DEBUG) && (CM_DEBUG > 1) if_printf(ifp, "intr: status 0x%02x, intmask 0x%02x\n", isr, sc->sc_intmask); #endif if (maskedisr & CM_POR) { /* * XXX We should never see this. Don't bother to store * the address. * sc->sc_ifp->if_l2com->ac_anaddr = GETMEM(CMMACOFF); */ PUTREG(CMCMD, CM_CLR(CLR_POR)); log(LOG_WARNING, "%s: intr: got spurious power on reset int\n", ifp->if_xname); } if (maskedisr & CM_RECON) { /* * we dont need to: * PUTREG(CMCMD, CM_CONF(CONF_LONG)); */ PUTREG(CMCMD, CM_CLR(CLR_RECONFIG)); if_inc_counter(ifp, IFCOUNTER_COLLISIONS, 1); /* * If less than 2 seconds per reconfig: * If ARC_EXCESSIVE_RECONFIGS * since last burst, complain and set treshold for * warnings to ARC_EXCESSIVE_RECONS_REWARN. * * This allows for, e.g., new stations on the cable, or * cable switching as long as it is over after * (normally) 16 seconds. * * XXX TODO: check timeout bits in status word and * double time if necessary. */ callout_stop(&sc->sc_recon_ch); newsec = time_second; if ((newsec - sc->sc_recontime <= 2) && (++sc->sc_reconcount == ARC_EXCESSIVE_RECONS)) { log(LOG_WARNING, "%s: excessive token losses, " "cable problem?\n", ifp->if_xname); } sc->sc_recontime = newsec; callout_reset(&sc->sc_recon_ch, 15 * hz, cm_reconwatch_locked, (void *)sc); } if (maskedisr & CM_RI) { #if defined(CM_DEBUG) && (CM_DEBUG > 1) if_printf(ifp, "intr: hard rint, act %d\n", sc->sc_rx_act); #endif buffer = sc->sc_rx_act; /* look if buffer is marked invalid: */ if (GETMEM(buffer * 512) == 0) { /* * invalid marked buffer (or illegally * configured sender) */ log(LOG_WARNING, "%s: spurious RX interrupt or sender 0 " " (ignored)\n", ifp->if_xname); /* * restart receiver on same buffer. * XXX maybe better reset interface? */ PUTREG(CMCMD, CM_RXBC(buffer)); } else { if (++sc->sc_rx_fillcount > 1) { sc->sc_intmask &= ~CM_RI; PUTREG(CMSTAT, sc->sc_intmask); } else { buffer ^= 1; sc->sc_rx_act = buffer; /* * Start receiver on other receive * buffer. This also clears the RI * interrupt flag. */ PUTREG(CMCMD, CM_RXBC(buffer)); /* in RX intr, so mask is ok for RX */ #ifdef CM_DEBUG if_printf(ifp, "strt rx for buf %d, " "stat 0x%02x\n", sc->sc_rx_act, GETREG(CMSTAT)); #endif } #ifdef CMSOFTCOPY /* * this one starts a soft int to copy out * of the hw */ softintr_schedule(sc->sc_rxcookie); #else /* this one does the copy here */ cm_srint_locked(sc); #endif } } if (maskedisr & CM_TA) { cm_tint_locked(sc, isr); } isr = GETREG(CMSTAT); maskedisr = isr & sc->sc_intmask; } while (maskedisr); #if defined(CM_DEBUG) && (CM_DEBUG > 1) if_printf(ifp, "intr (exit): status 0x%02x, intmask 0x%02x\n", isr, sc->sc_intmask); #endif CM_UNLOCK(sc); } void cm_reconwatch_locked(arg) void *arg; { struct cm_softc *sc = arg; struct ifnet *ifp = sc->sc_ifp; if (sc->sc_reconcount >= ARC_EXCESSIVE_RECONS) { sc->sc_reconcount = 0; log(LOG_WARNING, "%s: token valid again.\n", ifp->if_xname); } sc->sc_reconcount = 0; } /* * Process an ioctl request. * This code needs some work - it looks pretty ugly. */ int cm_ioctl(ifp, command, data) struct ifnet *ifp; u_long command; caddr_t data; { struct cm_softc *sc; int error; error = 0; sc = ifp->if_softc; #if defined(CM_DEBUG) && (CM_DEBUG > 2) if_printf(ifp, "ioctl() called, cmd = 0x%lx\n", command); #endif switch (command) { case SIOCSIFADDR: case SIOCGIFADDR: case SIOCADDMULTI: case SIOCDELMULTI: case SIOCSIFMTU: error = arc_ioctl(ifp, command, data); break; case SIOCSIFFLAGS: CM_LOCK(sc); if ((ifp->if_flags & IFF_UP) == 0 && (ifp->if_drv_flags & IFF_DRV_RUNNING) != 0) { /* * If interface is marked down and it is running, * then stop it. */ cm_stop_locked(sc); ifp->if_drv_flags &= ~IFF_DRV_RUNNING; } else if ((ifp->if_flags & IFF_UP) != 0 && (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { /* * If interface is marked up and it is stopped, then * start it. */ cm_init_locked(sc); } CM_UNLOCK(sc); break; default: error = EINVAL; break; } return (error); } /* * watchdog routine for transmitter. * * We need this, because else a receiver whose hardware is alive, but whose * software has not enabled the Receiver, would make our hardware wait forever * Discovered this after 20 times reading the docs. * * Only thing we do is disable transmitter. We'll get a transmit timeout, * and the int handler will have to decide not to retransmit (in case * retransmission is implemented). */ void cm_watchdog(void *arg) { struct cm_softc *sc; sc = arg; callout_reset(&sc->sc_watchdog_timer, hz, cm_watchdog, sc); if (sc->sc_timer == 0 || --sc->sc_timer > 0) return; PUTREG(CMCMD, CM_TXDIS); }