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- /*
- * slcan.c - serial line CAN interface driver (using tty line discipline)
- *
- * This file is derived from linux/drivers/net/slip/slip.c
- *
- * slip.c Authors : Laurence Culhane <loz@holmes.demon.co.uk>
- * Fred N. van Kempen <waltje@uwalt.nl.mugnet.org>
- * slcan.c Author : Oliver Hartkopp <socketcan@hartkopp.net>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, see http://www.gnu.org/licenses/gpl.html
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
- * OWNER 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.
- *
- */
- #include <linux/module.h>
- #include <linux/moduleparam.h>
- #include <linux/uaccess.h>
- #include <linux/bitops.h>
- #include <linux/string.h>
- #include <linux/tty.h>
- #include <linux/errno.h>
- #include <linux/netdevice.h>
- #include <linux/skbuff.h>
- #include <linux/rtnetlink.h>
- #include <linux/if_arp.h>
- #include <linux/if_ether.h>
- #include <linux/sched.h>
- #include <linux/delay.h>
- #include <linux/init.h>
- #include <linux/kernel.h>
- #include <linux/workqueue.h>
- #include <linux/can.h>
- #include <linux/can/skb.h>
- #include <linux/can/can-ml.h>
- MODULE_ALIAS_LDISC(N_SLCAN);
- MODULE_DESCRIPTION("serial line CAN interface");
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
- #define SLCAN_MAGIC 0x53CA
- static int maxdev = 10; /* MAX number of SLCAN channels;
- This can be overridden with
- insmod slcan.ko maxdev=nnn */
- module_param(maxdev, int, 0);
- MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces");
- /* maximum rx buffer len: extended CAN frame with timestamp */
- #define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r")+1)
- #define SLC_CMD_LEN 1
- #define SLC_SFF_ID_LEN 3
- #define SLC_EFF_ID_LEN 8
- struct slcan {
- int magic;
- /* Various fields. */
- struct tty_struct *tty; /* ptr to TTY structure */
- struct net_device *dev; /* easy for intr handling */
- spinlock_t lock;
- struct work_struct tx_work; /* Flushes transmit buffer */
- /* These are pointers to the malloc()ed frame buffers. */
- unsigned char rbuff[SLC_MTU]; /* receiver buffer */
- int rcount; /* received chars counter */
- unsigned char xbuff[SLC_MTU]; /* transmitter buffer */
- unsigned char *xhead; /* pointer to next XMIT byte */
- int xleft; /* bytes left in XMIT queue */
- unsigned long flags; /* Flag values/ mode etc */
- #define SLF_INUSE 0 /* Channel in use */
- #define SLF_ERROR 1 /* Parity, etc. error */
- };
- static struct net_device **slcan_devs;
- /************************************************************************
- * SLCAN ENCAPSULATION FORMAT *
- ************************************************************************/
- /*
- * A CAN frame has a can_id (11 bit standard frame format OR 29 bit extended
- * frame format) a data length code (can_dlc) which can be from 0 to 8
- * and up to <can_dlc> data bytes as payload.
- * Additionally a CAN frame may become a remote transmission frame if the
- * RTR-bit is set. This causes another ECU to send a CAN frame with the
- * given can_id.
- *
- * The SLCAN ASCII representation of these different frame types is:
- * <type> <id> <dlc> <data>*
- *
- * Extended frames (29 bit) are defined by capital characters in the type.
- * RTR frames are defined as 'r' types - normal frames have 't' type:
- * t => 11 bit data frame
- * r => 11 bit RTR frame
- * T => 29 bit data frame
- * R => 29 bit RTR frame
- *
- * The <id> is 3 (standard) or 8 (extended) bytes in ASCII Hex (base64).
- * The <dlc> is a one byte ASCII number ('0' - '8')
- * The <data> section has at much ASCII Hex bytes as defined by the <dlc>
- *
- * Examples:
- *
- * t1230 : can_id 0x123, can_dlc 0, no data
- * t4563112233 : can_id 0x456, can_dlc 3, data 0x11 0x22 0x33
- * T12ABCDEF2AA55 : extended can_id 0x12ABCDEF, can_dlc 2, data 0xAA 0x55
- * r1230 : can_id 0x123, can_dlc 0, no data, remote transmission request
- *
- */
- /************************************************************************
- * STANDARD SLCAN DECAPSULATION *
- ************************************************************************/
- /* Send one completely decapsulated can_frame to the network layer */
- static void slc_bump(struct slcan *sl)
- {
- struct sk_buff *skb;
- struct can_frame cf;
- int i, tmp;
- u32 tmpid;
- char *cmd = sl->rbuff;
- memset(&cf, 0, sizeof(cf));
- switch (*cmd) {
- case 'r':
- cf.can_id = CAN_RTR_FLAG;
- /* fallthrough */
- case 't':
- /* store dlc ASCII value and terminate SFF CAN ID string */
- cf.can_dlc = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN];
- sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN] = 0;
- /* point to payload data behind the dlc */
- cmd += SLC_CMD_LEN + SLC_SFF_ID_LEN + 1;
- break;
- case 'R':
- cf.can_id = CAN_RTR_FLAG;
- /* fallthrough */
- case 'T':
- cf.can_id |= CAN_EFF_FLAG;
- /* store dlc ASCII value and terminate EFF CAN ID string */
- cf.can_dlc = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN];
- sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN] = 0;
- /* point to payload data behind the dlc */
- cmd += SLC_CMD_LEN + SLC_EFF_ID_LEN + 1;
- break;
- default:
- return;
- }
- if (kstrtou32(sl->rbuff + SLC_CMD_LEN, 16, &tmpid))
- return;
- cf.can_id |= tmpid;
- /* get can_dlc from sanitized ASCII value */
- if (cf.can_dlc >= '0' && cf.can_dlc < '9')
- cf.can_dlc -= '0';
- else
- return;
- /* RTR frames may have a dlc > 0 but they never have any data bytes */
- if (!(cf.can_id & CAN_RTR_FLAG)) {
- for (i = 0; i < cf.can_dlc; i++) {
- tmp = hex_to_bin(*cmd++);
- if (tmp < 0)
- return;
- cf.data[i] = (tmp << 4);
- tmp = hex_to_bin(*cmd++);
- if (tmp < 0)
- return;
- cf.data[i] |= tmp;
- }
- }
- skb = dev_alloc_skb(sizeof(struct can_frame) +
- sizeof(struct can_skb_priv));
- if (!skb)
- return;
- skb->dev = sl->dev;
- skb->protocol = htons(ETH_P_CAN);
- skb->pkt_type = PACKET_BROADCAST;
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- can_skb_reserve(skb);
- can_skb_prv(skb)->ifindex = sl->dev->ifindex;
- can_skb_prv(skb)->skbcnt = 0;
- skb_put_data(skb, &cf, sizeof(struct can_frame));
- sl->dev->stats.rx_packets++;
- sl->dev->stats.rx_bytes += cf.can_dlc;
- netif_rx_ni(skb);
- }
- /* parse tty input stream */
- static void slcan_unesc(struct slcan *sl, unsigned char s)
- {
- if ((s == '\r') || (s == '\a')) { /* CR or BEL ends the pdu */
- if (!test_and_clear_bit(SLF_ERROR, &sl->flags) &&
- (sl->rcount > 4)) {
- slc_bump(sl);
- }
- sl->rcount = 0;
- } else {
- if (!test_bit(SLF_ERROR, &sl->flags)) {
- if (sl->rcount < SLC_MTU) {
- sl->rbuff[sl->rcount++] = s;
- return;
- } else {
- sl->dev->stats.rx_over_errors++;
- set_bit(SLF_ERROR, &sl->flags);
- }
- }
- }
- }
- /************************************************************************
- * STANDARD SLCAN ENCAPSULATION *
- ************************************************************************/
- /* Encapsulate one can_frame and stuff into a TTY queue. */
- static void slc_encaps(struct slcan *sl, struct can_frame *cf)
- {
- int actual, i;
- unsigned char *pos;
- unsigned char *endpos;
- canid_t id = cf->can_id;
- pos = sl->xbuff;
- if (cf->can_id & CAN_RTR_FLAG)
- *pos = 'R'; /* becomes 'r' in standard frame format (SFF) */
- else
- *pos = 'T'; /* becomes 't' in standard frame format (SSF) */
- /* determine number of chars for the CAN-identifier */
- if (cf->can_id & CAN_EFF_FLAG) {
- id &= CAN_EFF_MASK;
- endpos = pos + SLC_EFF_ID_LEN;
- } else {
- *pos |= 0x20; /* convert R/T to lower case for SFF */
- id &= CAN_SFF_MASK;
- endpos = pos + SLC_SFF_ID_LEN;
- }
- /* build 3 (SFF) or 8 (EFF) digit CAN identifier */
- pos++;
- while (endpos >= pos) {
- *endpos-- = hex_asc_upper[id & 0xf];
- id >>= 4;
- }
- pos += (cf->can_id & CAN_EFF_FLAG) ? SLC_EFF_ID_LEN : SLC_SFF_ID_LEN;
- *pos++ = cf->can_dlc + '0';
- /* RTR frames may have a dlc > 0 but they never have any data bytes */
- if (!(cf->can_id & CAN_RTR_FLAG)) {
- for (i = 0; i < cf->can_dlc; i++)
- pos = hex_byte_pack_upper(pos, cf->data[i]);
- }
- *pos++ = '\r';
- /* Order of next two lines is *very* important.
- * When we are sending a little amount of data,
- * the transfer may be completed inside the ops->write()
- * routine, because it's running with interrupts enabled.
- * In this case we *never* got WRITE_WAKEUP event,
- * if we did not request it before write operation.
- * 14 Oct 1994 Dmitry Gorodchanin.
- */
- set_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
- actual = sl->tty->ops->write(sl->tty, sl->xbuff, pos - sl->xbuff);
- sl->xleft = (pos - sl->xbuff) - actual;
- sl->xhead = sl->xbuff + actual;
- sl->dev->stats.tx_bytes += cf->can_dlc;
- }
- /* Write out any remaining transmit buffer. Scheduled when tty is writable */
- static void slcan_transmit(struct work_struct *work)
- {
- struct slcan *sl = container_of(work, struct slcan, tx_work);
- int actual;
- spin_lock_bh(&sl->lock);
- /* First make sure we're connected. */
- if (!sl->tty || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) {
- spin_unlock_bh(&sl->lock);
- return;
- }
- if (sl->xleft <= 0) {
- /* Now serial buffer is almost free & we can start
- * transmission of another packet */
- sl->dev->stats.tx_packets++;
- clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
- spin_unlock_bh(&sl->lock);
- netif_wake_queue(sl->dev);
- return;
- }
- actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft);
- sl->xleft -= actual;
- sl->xhead += actual;
- spin_unlock_bh(&sl->lock);
- }
- /*
- * Called by the driver when there's room for more data.
- * Schedule the transmit.
- */
- static void slcan_write_wakeup(struct tty_struct *tty)
- {
- struct slcan *sl;
- rcu_read_lock();
- sl = rcu_dereference(tty->disc_data);
- if (!sl)
- goto out;
- schedule_work(&sl->tx_work);
- out:
- rcu_read_unlock();
- }
- /* Send a can_frame to a TTY queue. */
- static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev)
- {
- struct slcan *sl = netdev_priv(dev);
- if (skb->len != CAN_MTU)
- goto out;
- spin_lock(&sl->lock);
- if (!netif_running(dev)) {
- spin_unlock(&sl->lock);
- printk(KERN_WARNING "%s: xmit: iface is down\n", dev->name);
- goto out;
- }
- if (sl->tty == NULL) {
- spin_unlock(&sl->lock);
- goto out;
- }
- netif_stop_queue(sl->dev);
- slc_encaps(sl, (struct can_frame *) skb->data); /* encaps & send */
- spin_unlock(&sl->lock);
- out:
- kfree_skb(skb);
- return NETDEV_TX_OK;
- }
- /******************************************
- * Routines looking at netdevice side.
- ******************************************/
- /* Netdevice UP -> DOWN routine */
- static int slc_close(struct net_device *dev)
- {
- struct slcan *sl = netdev_priv(dev);
- spin_lock_bh(&sl->lock);
- if (sl->tty) {
- /* TTY discipline is running. */
- clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
- }
- netif_stop_queue(dev);
- sl->rcount = 0;
- sl->xleft = 0;
- spin_unlock_bh(&sl->lock);
- return 0;
- }
- /* Netdevice DOWN -> UP routine */
- static int slc_open(struct net_device *dev)
- {
- struct slcan *sl = netdev_priv(dev);
- if (sl->tty == NULL)
- return -ENODEV;
- sl->flags &= (1 << SLF_INUSE);
- netif_start_queue(dev);
- return 0;
- }
- /* Hook the destructor so we can free slcan devs at the right point in time */
- static void slc_free_netdev(struct net_device *dev)
- {
- int i = dev->base_addr;
- slcan_devs[i] = NULL;
- }
- static int slcan_change_mtu(struct net_device *dev, int new_mtu)
- {
- return -EINVAL;
- }
- static const struct net_device_ops slc_netdev_ops = {
- .ndo_open = slc_open,
- .ndo_stop = slc_close,
- .ndo_start_xmit = slc_xmit,
- .ndo_change_mtu = slcan_change_mtu,
- };
- static void slc_setup(struct net_device *dev)
- {
- dev->netdev_ops = &slc_netdev_ops;
- dev->needs_free_netdev = true;
- dev->priv_destructor = slc_free_netdev;
- dev->hard_header_len = 0;
- dev->addr_len = 0;
- dev->tx_queue_len = 10;
- dev->mtu = CAN_MTU;
- dev->type = ARPHRD_CAN;
- /* New-style flags. */
- dev->flags = IFF_NOARP;
- dev->features = NETIF_F_HW_CSUM;
- }
- /******************************************
- Routines looking at TTY side.
- ******************************************/
- /*
- * Handle the 'receiver data ready' interrupt.
- * This function is called by the 'tty_io' module in the kernel when
- * a block of SLCAN data has been received, which can now be decapsulated
- * and sent on to some IP layer for further processing. This will not
- * be re-entered while running but other ldisc functions may be called
- * in parallel
- */
- static void slcan_receive_buf(struct tty_struct *tty,
- const unsigned char *cp, char *fp, int count)
- {
- struct slcan *sl = (struct slcan *) tty->disc_data;
- if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev))
- return;
- /* Read the characters out of the buffer */
- while (count--) {
- if (fp && *fp++) {
- if (!test_and_set_bit(SLF_ERROR, &sl->flags))
- sl->dev->stats.rx_errors++;
- cp++;
- continue;
- }
- slcan_unesc(sl, *cp++);
- }
- }
- /************************************
- * slcan_open helper routines.
- ************************************/
- /* Collect hanged up channels */
- static void slc_sync(void)
- {
- int i;
- struct net_device *dev;
- struct slcan *sl;
- for (i = 0; i < maxdev; i++) {
- dev = slcan_devs[i];
- if (dev == NULL)
- break;
- sl = netdev_priv(dev);
- if (sl->tty)
- continue;
- if (dev->flags & IFF_UP)
- dev_close(dev);
- }
- }
- /* Find a free SLCAN channel, and link in this `tty' line. */
- static struct slcan *slc_alloc(void)
- {
- int i;
- char name[IFNAMSIZ];
- struct net_device *dev = NULL;
- struct can_ml_priv *can_ml;
- struct slcan *sl;
- int size;
- for (i = 0; i < maxdev; i++) {
- dev = slcan_devs[i];
- if (dev == NULL)
- break;
- }
- /* Sorry, too many, all slots in use */
- if (i >= maxdev)
- return NULL;
- sprintf(name, "slcan%d", i);
- size = ALIGN(sizeof(*sl), NETDEV_ALIGN) + sizeof(struct can_ml_priv);
- dev = alloc_netdev(size, name, NET_NAME_UNKNOWN, slc_setup);
- if (!dev)
- return NULL;
- dev->base_addr = i;
- sl = netdev_priv(dev);
- can_ml = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN);
- can_set_ml_priv(dev, can_ml);
- /* Initialize channel control data */
- sl->magic = SLCAN_MAGIC;
- sl->dev = dev;
- spin_lock_init(&sl->lock);
- INIT_WORK(&sl->tx_work, slcan_transmit);
- slcan_devs[i] = dev;
- return sl;
- }
- /*
- * Open the high-level part of the SLCAN channel.
- * This function is called by the TTY module when the
- * SLCAN line discipline is called for. Because we are
- * sure the tty line exists, we only have to link it to
- * a free SLCAN channel...
- *
- * Called in process context serialized from other ldisc calls.
- */
- static int slcan_open(struct tty_struct *tty)
- {
- struct slcan *sl;
- int err;
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
- if (tty->ops->write == NULL)
- return -EOPNOTSUPP;
- /* RTnetlink lock is misused here to serialize concurrent
- opens of slcan channels. There are better ways, but it is
- the simplest one.
- */
- rtnl_lock();
- /* Collect hanged up channels. */
- slc_sync();
- sl = tty->disc_data;
- err = -EEXIST;
- /* First make sure we're not already connected. */
- if (sl && sl->magic == SLCAN_MAGIC)
- goto err_exit;
- /* OK. Find a free SLCAN channel to use. */
- err = -ENFILE;
- sl = slc_alloc();
- if (sl == NULL)
- goto err_exit;
- sl->tty = tty;
- tty->disc_data = sl;
- if (!test_bit(SLF_INUSE, &sl->flags)) {
- /* Perform the low-level SLCAN initialization. */
- sl->rcount = 0;
- sl->xleft = 0;
- set_bit(SLF_INUSE, &sl->flags);
- err = register_netdevice(sl->dev);
- if (err)
- goto err_free_chan;
- }
- /* Done. We have linked the TTY line to a channel. */
- rtnl_unlock();
- tty->receive_room = 65536; /* We don't flow control */
- /* TTY layer expects 0 on success */
- return 0;
- err_free_chan:
- sl->tty = NULL;
- tty->disc_data = NULL;
- clear_bit(SLF_INUSE, &sl->flags);
- slc_free_netdev(sl->dev);
- /* do not call free_netdev before rtnl_unlock */
- rtnl_unlock();
- free_netdev(sl->dev);
- return err;
- err_exit:
- rtnl_unlock();
- /* Count references from TTY module */
- return err;
- }
- /*
- * Close down a SLCAN channel.
- * This means flushing out any pending queues, and then returning. This
- * call is serialized against other ldisc functions.
- *
- * We also use this method for a hangup event.
- */
- static void slcan_close(struct tty_struct *tty)
- {
- struct slcan *sl = (struct slcan *) tty->disc_data;
- /* First make sure we're connected. */
- if (!sl || sl->magic != SLCAN_MAGIC || sl->tty != tty)
- return;
- spin_lock_bh(&sl->lock);
- rcu_assign_pointer(tty->disc_data, NULL);
- sl->tty = NULL;
- spin_unlock_bh(&sl->lock);
- synchronize_rcu();
- flush_work(&sl->tx_work);
- /* Flush network side */
- unregister_netdev(sl->dev);
- /* This will complete via sl_free_netdev */
- }
- static int slcan_hangup(struct tty_struct *tty)
- {
- slcan_close(tty);
- return 0;
- }
- /* Perform I/O control on an active SLCAN channel. */
- static int slcan_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
- {
- struct slcan *sl = (struct slcan *) tty->disc_data;
- unsigned int tmp;
- /* First make sure we're connected. */
- if (!sl || sl->magic != SLCAN_MAGIC)
- return -EINVAL;
- switch (cmd) {
- case SIOCGIFNAME:
- tmp = strlen(sl->dev->name) + 1;
- if (copy_to_user((void __user *)arg, sl->dev->name, tmp))
- return -EFAULT;
- return 0;
- case SIOCSIFHWADDR:
- return -EINVAL;
- default:
- return tty_mode_ioctl(tty, file, cmd, arg);
- }
- }
- static struct tty_ldisc_ops slc_ldisc = {
- .owner = THIS_MODULE,
- .magic = TTY_LDISC_MAGIC,
- .name = "slcan",
- .open = slcan_open,
- .close = slcan_close,
- .hangup = slcan_hangup,
- .ioctl = slcan_ioctl,
- .receive_buf = slcan_receive_buf,
- .write_wakeup = slcan_write_wakeup,
- };
- static int __init slcan_init(void)
- {
- int status;
- if (maxdev < 4)
- maxdev = 4; /* Sanity */
- pr_info("slcan: serial line CAN interface driver\n");
- pr_info("slcan: %d dynamic interface channels.\n", maxdev);
- slcan_devs = kcalloc(maxdev, sizeof(struct net_device *), GFP_KERNEL);
- if (!slcan_devs)
- return -ENOMEM;
- /* Fill in our line protocol discipline, and register it */
- status = tty_register_ldisc(N_SLCAN, &slc_ldisc);
- if (status) {
- printk(KERN_ERR "slcan: can't register line discipline\n");
- kfree(slcan_devs);
- }
- return status;
- }
- static void __exit slcan_exit(void)
- {
- int i;
- struct net_device *dev;
- struct slcan *sl;
- unsigned long timeout = jiffies + HZ;
- int busy = 0;
- if (slcan_devs == NULL)
- return;
- /* First of all: check for active disciplines and hangup them.
- */
- do {
- if (busy)
- msleep_interruptible(100);
- busy = 0;
- for (i = 0; i < maxdev; i++) {
- dev = slcan_devs[i];
- if (!dev)
- continue;
- sl = netdev_priv(dev);
- spin_lock_bh(&sl->lock);
- if (sl->tty) {
- busy++;
- tty_hangup(sl->tty);
- }
- spin_unlock_bh(&sl->lock);
- }
- } while (busy && time_before(jiffies, timeout));
- /* FIXME: hangup is async so we should wait when doing this second
- phase */
- for (i = 0; i < maxdev; i++) {
- dev = slcan_devs[i];
- if (!dev)
- continue;
- slcan_devs[i] = NULL;
- sl = netdev_priv(dev);
- if (sl->tty) {
- printk(KERN_ERR "%s: tty discipline still running\n",
- dev->name);
- }
- unregister_netdev(dev);
- }
- kfree(slcan_devs);
- slcan_devs = NULL;
- i = tty_unregister_ldisc(N_SLCAN);
- if (i)
- printk(KERN_ERR "slcan: can't unregister ldisc (err %d)\n", i);
- }
- module_init(slcan_init);
- module_exit(slcan_exit);
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