V4L/DVB (6279): en_50221: convert to kthread API

Here's an attempted update to the full kthread API + wake_up_process:

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
CC: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 16 insertions, 68 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
index 5c7bcb8393d2..084a508a03da 100644
--- a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
@@ -36,6 +36,7 @@
 #include <linux/delay.h>
 #include <linux/spinlock.h>
 #include <linux/sched.h>
+#include <linux/kthread.h>
 
 #include "dvb_ca_en50221.h"
 #include "dvb_ringbuffer.h"
@@ -139,13 +140,7 @@ struct dvb_ca_private {
         wait_queue_head_t wait_queue;
 
         /* PID of the monitoring thread */
-        pid_t thread_pid;
-
-        /* Wait queue used when shutting thread down */
-        wait_queue_head_t thread_queue;
-
-        /* Flag indicating when thread should exit */
-        unsigned int exit:1;
+        struct task_struct *thread;
 
         /* Flag indicating if the CA device is open */
         unsigned int open:1;
@@ -901,28 +896,10 @@ static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca)
 
         ca->wakeup = 1;
         mb();
-        wake_up_interruptible(&ca->thread_queue);
+        wake_up_process(ca->thread);
 }
 
 /**
- * Used by the CA thread to determine if an early wakeup is necessary
- *
- * @param ca CA instance.
- */
-static int dvb_ca_en50221_thread_should_wakeup(struct dvb_ca_private *ca)
-{
-        if (ca->wakeup) {
-                ca->wakeup = 0;
-                return 1;
-        }
-        if (ca->exit)
-                return 1;
-
-        return 0;
-}
-
-
-/**
  * Update the delay used by the thread.
  *
  * @param ca CA instance.
@@ -981,7 +958,6 @@ static void dvb_ca_en50221_thread_update_delay(struct dvb_ca_private *ca)
 static int dvb_ca_en50221_thread(void *data)
 {
         struct dvb_ca_private *ca = data;
-        char name[15];
         int slot;
         int flags;
         int status;
@@ -990,28 +966,17 @@ static int dvb_ca_en50221_thread(void *data)
 
         dprintk("%s\n", __FUNCTION__);
 
-        /* setup kernel thread */
-        snprintf(name, sizeof(name), "kdvb-ca-%i:%i", ca->dvbdev->adapter->num, ca->dvbdev->id);
-
-        lock_kernel();
-        daemonize(name);
-        sigfillset(&current->blocked);
-        unlock_kernel();
-
         /* choose the correct initial delay */
         dvb_ca_en50221_thread_update_delay(ca);
 
         /* main loop */
-        while (!ca->exit) {
+        while (!kthread_should_stop()) {
                 /* sleep for a bit */
-                if (!ca->wakeup) {
-                        flags = wait_event_interruptible_timeout(ca->thread_queue,
-                                                                 dvb_ca_en50221_thread_should_wakeup(ca),
-                                                                 ca->delay);
-                        if ((flags == -ERESTARTSYS) || ca->exit) {
-                                /* got signal or quitting */
-                                break;
-                        }
+                while (!ca->wakeup) {
+                        set_current_state(TASK_INTERRUPTIBLE);
+                        schedule_timeout(ca->delay);
+                        if (kthread_should_stop())
+                                return 0;
                 }
                 ca->wakeup = 0;
 
@@ -1180,10 +1145,6 @@ static int dvb_ca_en50221_thread(void *data)
                 }
         }
 
-        /* completed */
-        ca->thread_pid = 0;
-        mb();
-        wake_up_interruptible(&ca->thread_queue);
         return 0;
 }
 
@@ -1683,9 +1644,6 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
                 goto error;
         }
         init_waitqueue_head(&ca->wait_queue);
-        ca->thread_pid = 0;
-        init_waitqueue_head(&ca->thread_queue);
-        ca->exit = 0;
         ca->open = 0;
         ca->wakeup = 0;
         ca->next_read_slot = 0;
@@ -1711,14 +1669,14 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
         mb();
 
         /* create a kthread for monitoring this CA device */
-
-        ret = kernel_thread(dvb_ca_en50221_thread, ca, 0);
-
-        if (ret < 0) {
-                printk("dvb_ca_init: failed to start kernel_thread (%d)\n", ret);
+        ca->thread = kthread_run(dvb_ca_en50221_thread, ca, "kdvb-ca-%i:%i",
+                                 ca->dvbdev->adapter->num, ca->dvbdev->id);
+        if (IS_ERR(ca->thread)) {
+                ret = PTR_ERR(ca->thread);
+                printk("dvb_ca_init: failed to start kernel_thread (%d)\n",
+                        ret);
                 goto error;
         }
-        ca->thread_pid = ret;
         return 0;
 
 error:
@@ -1749,17 +1707,7 @@ void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
         dprintk("%s\n", __FUNCTION__);
 
         /* shutdown the thread if there was one */
-        if (ca->thread_pid) {
-                if (kill_proc(ca->thread_pid, 0, 1) == -ESRCH) {
-                        printk("dvb_ca_release adapter %d: thread PID %d already died\n",
-                               ca->dvbdev->adapter->num, ca->thread_pid);
-                } else {
-                        ca->exit = 1;
-                        mb();
-                        dvb_ca_en50221_thread_wakeup(ca);
-                        wait_event_interruptible(ca->thread_queue, ca->thread_pid == 0);
-                }
-        }
+        kthread_stop(ca->thread);
 
         for (i = 0; i < ca->slot_count; i++) {
                 dvb_ca_en50221_slot_shutdown(ca, i);