diff options
Diffstat (limited to 'drivers/net/can/slcan.c')
| -rw-r--r-- | drivers/net/can/slcan.c | 51 |
1 files changed, 36 insertions, 15 deletions
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 25377e547f9..ea4d4f1a641 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -18,9 +18,7 @@ * General Public License for more details. * * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307. You can also get it - * at http://www.gnu.org/licenses/gpl.html + * 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 @@ -54,6 +52,7 @@ #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> @@ -87,6 +86,7 @@ struct slcan { 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 */ @@ -311,34 +311,44 @@ static void slc_encaps(struct slcan *sl, struct can_frame *cf) sl->dev->stats.tx_bytes += cf->can_dlc; } -/* - * Called by the driver when there's room for more data. If we have - * more packets to send, we send them here. - */ -static void slcan_write_wakeup(struct tty_struct *tty) +/* 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; - struct slcan *sl = (struct slcan *) tty->disc_data; + spin_lock_bh(&sl->lock); /* First make sure we're connected. */ - if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) + if (!sl->tty || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) { + spin_unlock_bh(&sl->lock); return; + } - spin_lock(&sl->lock); 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, &tty->flags); - spin_unlock(&sl->lock); + clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + spin_unlock_bh(&sl->lock); netif_wake_queue(sl->dev); return; } - actual = tty->ops->write(tty, sl->xhead, sl->xleft); + actual = sl->tty->ops->write(sl->tty, sl->xhead, sl->xleft); sl->xleft -= actual; sl->xhead += actual; - spin_unlock(&sl->lock); + 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 = tty->disc_data; + + schedule_work(&sl->tx_work); } /* Send a can_frame to a TTY queue. */ @@ -413,10 +423,16 @@ static void slc_free_netdev(struct net_device *dev) 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) @@ -524,6 +540,7 @@ static struct slcan *slc_alloc(dev_t line) 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; @@ -622,8 +639,12 @@ static void slcan_close(struct tty_struct *tty) if (!sl || sl->magic != SLCAN_MAGIC || sl->tty != tty) return; + spin_lock_bh(&sl->lock); tty->disc_data = NULL; sl->tty = NULL; + spin_unlock_bh(&sl->lock); + + flush_work(&sl->tx_work); /* Flush network side */ unregister_netdev(sl->dev); |