Added minimal skeleton to use kernel worker thread.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

diff --git a/sllin/sllin.c b/sllin/sllin.c
index ce8709fa61f71063ca1c980638dc3ab11d00476a..77935414bcd3a172e7d591940b740c76fe4966e6 100644 (file)
--- a/sllin/sllin.c
+++ b/sllin/sllin.c
@@ -57,6 +57,7 @@
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/can.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/can.h>

+#include <linux/kthread.h>

 
 /* Should be in include/linux/tty.h */
 #define N_SLLIN         25
 
 /* Should be in include/linux/tty.h */
 #define N_SLLIN         25


@@ -101,7 +102,8 @@ struct sllin {
 
        unsigned char           leased;
        dev_t                   line;
 
        unsigned char           leased;
        dev_t                   line;

-       pid_t                   pid;
+       struct task_struct      *kwthread;
+       wait_queue_head_t       kwt_wq;

 };
 
 static struct net_device **sllin_devs;
 };
 
 static struct net_device **sllin_devs;


@@ -233,7 +235,7 @@ static void sll_encaps(struct sllin *sl, struct can_frame *cf)
 
        /* Send only header */
        if (cf->can_id & CAN_RTR_FLAG) {
 
        /* Send only header */
        if (cf->can_id & CAN_RTR_FLAG) {

-               pr_debug("sllin: RTR CAN frame\n", __FUNCTION__);
+               pr_debug("sllin: %s() RTR CAN frame\n", __FUNCTION__);

                lframe[2] = (u8)cf->can_id; /* Get one byte LIN ID */
 
                sltty_change_speed(tty, 1200);
                lframe[2] = (u8)cf->can_id; /* Get one byte LIN ID */
 
                sltty_change_speed(tty, 1200);


@@ -242,7 +244,7 @@ static void sll_encaps(struct sllin *sl, struct can_frame *cf)
                tty->ops->write(tty, &lframe[1], 1);
                tty->ops->write(tty, &lframe[2], 1);
        } else {
                tty->ops->write(tty, &lframe[1], 1);
                tty->ops->write(tty, &lframe[2], 1);
        } else {

-               pr_debug("sllin: non-RTR CAN frame\n", __FUNCTION__);
+               pr_debug("sllin: %s() non-RTR CAN frame\n", __FUNCTION__);

                /*      idx = strlen(sl->xbuff);
 
                        for (i = 0; i < cf->can_dlc; i++)
                /*      idx = strlen(sl->xbuff);
 
                        for (i = 0; i < cf->can_dlc; i++)


@@ -423,6 +425,28 @@ static void sllin_receive_buf(struct tty_struct *tty,
        }
 }
 
        }
 }
 

+/*****************************************
+ *  sllin_kwthread - kernel worker thread
+ *****************************************/
+
+int sllin_kwthread(void *ptr)
+{
+       struct sllin *sl = (struct sllin *)ptr;
+
+       printk(KERN_INFO "sllin: sllin_kwthread started.\n");
+
+       while (!kthread_should_stop()) {
+               
+               wait_event_killable(sl->kwt_wq, kthread_should_stop());
+
+       }
+
+       printk(KERN_INFO "sllin: sllin_kwthread stopped.\n");
+
+       return 0;
+}
+
+

 /************************************
  *  sllin_open helper routines.
  ************************************/
 /************************************
  *  sllin_open helper routines.
  ************************************/


@@ -545,7 +569,6 @@ static int sllin_open(struct tty_struct *tty)
        sl->tty = tty;
        tty->disc_data = sl;
        sl->line = tty_devnum(tty);
        sl->tty = tty;
        tty->disc_data = sl;
        sl->line = tty_devnum(tty);

-       sl->pid = current->pid;

 
        if (!test_bit(SLF_INUSE, &sl->flags)) {
                /* Perform the low-level SLLIN initialization. */
 
        if (!test_bit(SLF_INUSE, &sl->flags)) {
                /* Perform the low-level SLLIN initialization. */


@@ -554,9 +577,14 @@ static int sllin_open(struct tty_struct *tty)
 
                set_bit(SLF_INUSE, &sl->flags);
 
 
                set_bit(SLF_INUSE, &sl->flags);
 

+               init_waitqueue_head(&sl->kwt_wq);
+               sl->kwthread = kthread_run(sllin_kwthread, sl, "sllin");
+               if (sl->kwthread == NULL)
+                       goto err_free_chan;
+

                err = register_netdevice(sl->dev);
                if (err)
                err = register_netdevice(sl->dev);
                if (err)

-                       goto err_free_chan;
+                       goto err_free_chan_and_thread;

        }
 
        /* Done.  We have linked the TTY line to a channel. */
        }
 
        /* Done.  We have linked the TTY line to a channel. */


@@ -566,6 +594,10 @@ static int sllin_open(struct tty_struct *tty)
        /* TTY layer expects 0 on success */
        return 0;
 
        /* TTY layer expects 0 on success */
        return 0;
 

+err_free_chan_and_thread:
+       kthread_stop(sl->kwthread);
+       sl->kwthread = NULL;
+

 err_free_chan:
        sl->tty = NULL;
        tty->disc_data = NULL;
 err_free_chan:
        sl->tty = NULL;
        tty->disc_data = NULL;


@@ -594,6 +626,9 @@ static void sllin_close(struct tty_struct *tty)
        if (!sl || sl->magic != SLLIN_MAGIC || sl->tty != tty)
                return;
 
        if (!sl || sl->magic != SLLIN_MAGIC || sl->tty != tty)
                return;
 

+       kthread_stop(sl->kwthread);
+       sl->kwthread = NULL;
+

        tty->disc_data = NULL;
        sl->tty = NULL;
        if (!sl->leased)
        tty->disc_data = NULL;
        sl->tty = NULL;
        if (!sl->leased)