V4L/DVB (4624): Tvaudio: Replaced kernel_thread() with kthread_run()

Replaced kernel_thread() with kthread_run() since kernel_thread() is
deprecated in drivers/modules.
Removed the completion and the wait queue which are now useless with
kthread. Also removed the allow_signal() call as signals don't apply
to kernel threads.
Fixed a small race condition when thread is stopped.
Please check if the timer vs. thread still works fine without the wait
queue.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 16 insertions, 26 deletions

diff --git a/drivers/media/video/tvaudio.c b/drivers/media/video/tvaudio.c
index 936e3f746fba..fcaef4bf8289 100644
--- a/drivers/media/video/tvaudio.c
+++ b/drivers/media/video/tvaudio.c
@@ -28,6 +28,7 @@
 #include <linux/i2c-algo-bit.h>
 #include <linux/init.h>
 #include <linux/smp_lock.h>
+#include <linux/kthread.h>
 
 #include <media/tvaudio.h>
 #include <media/v4l2-common.h>
@@ -124,11 +125,8 @@ struct CHIPSTATE {
         int input;
 
         /* thread */
-        pid_t                tpid;
-        struct completion    texit;
-        wait_queue_head_t    wq;
+        struct task_struct   *thread;
         struct timer_list    wt;
-        int                  done;
         int                  watch_stereo;
         int                  audmode;
 };
@@ -264,28 +262,23 @@ static int chip_cmd(struct CHIPSTATE *chip, char *name, audiocmd *cmd)
 static void chip_thread_wake(unsigned long data)
 {
         struct CHIPSTATE *chip = (struct CHIPSTATE*)data;
-        wake_up_interruptible(&chip->wq);
+        wake_up_process(chip->thread);
 }
 
 static int chip_thread(void *data)
 {
-        DECLARE_WAITQUEUE(wait, current);
         struct CHIPSTATE *chip = data;
         struct CHIPDESC  *desc = chiplist + chip->type;
 
-        daemonize("%s", chip->c.name);
-        allow_signal(SIGTERM);
         v4l_dbg(1, debug, &chip->c, "%s: thread started\n", chip->c.name);
 
         for (;;) {
-                add_wait_queue(&chip->wq, &wait);
-                if (!chip->done) {
-                        set_current_state(TASK_INTERRUPTIBLE);
+                set_current_state(TASK_INTERRUPTIBLE);
+                if (!kthread_should_stop())
                         schedule();
-                }
-                remove_wait_queue(&chip->wq, &wait);
+                set_current_state(TASK_RUNNING);
                 try_to_freeze();
-                if (chip->done || signal_pending(current))
+                if (kthread_should_stop())
                         break;
                 v4l_dbg(1, debug, &chip->c, "%s: thread wakeup\n", chip->c.name);
 
@@ -301,7 +294,6 @@ static int chip_thread(void *data)
         }
 
         v4l_dbg(1, debug, &chip->c, "%s: thread exiting\n", chip->c.name);
-        complete_and_exit(&chip->texit, 0);
         return 0;
 }
 
@@ -1536,19 +1528,18 @@ static int chip_attach(struct i2c_adapter *adap, int addr, int kind)
                 chip_write(chip,desc->treblereg,desc->treblefunc(chip->treble));
         }
 
-        chip->tpid = -1;
+        chip->thread = NULL;
         if (desc->checkmode) {
                 /* start async thread */
                 init_timer(&chip->wt);
                 chip->wt.function = chip_thread_wake;
                 chip->wt.data     = (unsigned long)chip;
-                init_waitqueue_head(&chip->wq);
-                init_completion(&chip->texit);
-                chip->tpid = kernel_thread(chip_thread,(void *)chip,0);
-                if (chip->tpid < 0)
-                        v4l_warn(&chip->c, "%s: kernel_thread() failed\n",
+                chip->thread = kthread_run(chip_thread, chip, chip->c.name);
+                if (IS_ERR(chip->thread)) {
+                        v4l_warn(&chip->c, "%s: failed to create kthread\n",
                                chip->c.name);
-                wake_up_interruptible(&chip->wq);
+                        chip->thread = NULL;
+                }
         }
         return 0;
 }
@@ -1569,11 +1560,10 @@ static int chip_detach(struct i2c_client *client)
         struct CHIPSTATE *chip = i2c_get_clientdata(client);
 
         del_timer_sync(&chip->wt);
-        if (chip->tpid >= 0) {
+        if (chip->thread) {
                 /* shutdown async thread */
-                chip->done = 1;
-                wake_up_interruptible(&chip->wq);
-                wait_for_completion(&chip->texit);
+                kthread_stop(chip->thread);
+                chip->thread = NULL;
         }
 
         i2c_detach_client(&chip->c);